Quantum http://feed.informer.com/digests/EYA8NJRRWR/feeder Quantum Respective post owners and feed distributors Tue, 26 Jun 2018 00:20:24 +0000 Feed Informer http://feed.informer.com/ From shtetl to Forum https://www.scottaaronson.com/blog/?p=4536 Shtetl-Optimized urn:uuid:ca96d452-3758-ce7d-b7c6-1e457f89ce9e Sat, 18 Jan 2020 13:40:50 +0000 Today I&#8217;m headed to the 50th World Economic Forum in Davos, where on Tuesday I&#8217;ll participate in a panel discussion on &#8220;The Quantum Potential&#8221; with Jeremy O&#8217;Brien of PsiQuantum, and will also host an ask-me-anything session about quantum computational supremacy and Google&#8217;s claim to have achieved it. I&#8217;m well aware that this will be unlike [&#8230;] <p>Today I&#8217;m headed to the <a href="https://www.weforum.org/events/world-economic-forum-annual-meeting-2020">50th World Economic Forum</a> in Davos, where on Tuesday I&#8217;ll participate in a <a href="https://www.weforum.org/events/world-economic-forum-annual-meeting-2020/sessions/the-quantum-potential">panel discussion</a> on &#8220;The Quantum Potential&#8221; with Jeremy O&#8217;Brien of <a href="https://psiquantum.com/">PsiQuantum</a>, and will also host an ask-me-anything session about quantum computational supremacy and Google&#8217;s claim to have achieved it.</p> <p>I&#8217;m well aware that this will be unlike any other conference I&#8217;ve ever attended: STOC or FOCS it ain&#8217;t. As one example, also speaking on Tuesday&#8212;although not conflicting with my QC sessions&#8212;will be a real-estate swindler and reality-TV star who&#8217;s somehow (alas) the current President of the United States. Yes, even while his impeachment trial in the Senate gets underway. <em>Also</em> speaking on Tuesday, a mere hour and a half after him, will be TIME&#8217;s Person of the Year, 17-year-old activist Greta Thunberg.</p> <p>In short, this Davos is shaping up to be an epic showdown between two diametrically opposed visions for the future of life on Earth. And your humble blogger will be right there in the middle of it, to &#8230; uhh &#8230; explain how quantum computers can sample probability distributions that are classically intractable unless the polynomial hierarchy collapses to the third level. I feel appropriately sheepish.</p> <p>Since the experience will be so unusual for me, I&#8217;m planning to <strong>&#8220;live-blog Davos&#8221;</strong>: I&#8217;ll be updating this post, all week, with any strange new things I see or learn. As a sign of my devotion to you, my loyal readers, I&#8217;ll even clothespin my nose and attend Trump&#8217;s speech so I can write about it.</p> <p>And Greta: on the off chance that you happen to read <em>Shtetl-Optimized</em>, let me treat you to a vegan lunch or dinner! I&#8217;d like to try to persuade you of just how essential nuclear power will be to a carbon-free future. Oh, and if it&#8217;s not too much trouble, I&#8217;d also like a selfie with you for this blog. (Alas, a friend pointed out to me that it would probably be easier to meet Trump: unlike Greta, he won&#8217;t be swarmed with thousands of fans!)</p> <p>Anyway, check back here throughout the week for updates. And please use the comment section to give me your advice, suggestions, well-wishes, requests, or important messages for me to fail to deliver to the &#8220;Davoisie&#8221; who rule the world.</p> Adventures in Meatspace Announcements Nerd Interest Scott How sensitive can a quantum detector be? https://www.sciencedaily.com/releases/2020/01/200117080821.htm Quantum Computers News -- ScienceDaily urn:uuid:39db2c69-f643-a09e-2ced-3f827ab9e270 Fri, 17 Jan 2020 13:08:21 +0000 Measuring the energy of quantum states requires detecting energy changes so exceptionally small they are hard to pick out from background fluctuations, like using only a thermometer to try and work out if someone has blown out a candle in the room you're in. New research presents sensitive quantum thermometry hitting the bounds that nature allows. An alternative argument for why women leave STEM: Guest post by Karen Morenz https://www.scottaaronson.com/blog/?p=4522 Shtetl-Optimized urn:uuid:d02898e6-a115-0f99-e885-907751bdb7eb Thu, 16 Jan 2020 20:21:42 +0000 Scott&#8217;s preface: Imagine that every time you turned your blog over to a certain topic, you got denounced on Twitter and Reddit as a privileged douchebro, entitled STEMlord, counterrevolutionary bourgeoisie, etc. etc. The sane response would simply be to quit blogging about that topic. But there&#8217;s also an insane (or masochistic?) response: the response that [&#8230;] <p><strong>Scott&#8217;s preface:</strong> Imagine that every time you turned your blog over to a certain topic, you got denounced on Twitter and Reddit as a privileged douchebro, entitled STEMlord, counterrevolutionary bourgeoisie, etc. etc. The sane response would simply be to quit blogging about that topic. But there&#8217;s also an <em>in</em>sane (or masochistic?) response: the response that says, &#8220;but if everyone like me stopped talking, we&#8217;d cede the field by default to the loudest, angriest voices on all sides&#8212;thereby giving those voices exactly what they wanted. To hell with that!&#8221;</p> <p>A few weeks ago, while I was being attacked for sharing Steven Pinker&#8217;s <a href="https://www.scottaaronson.com/blog/?p=4476">guest post</a> about NIPS vs. NeurIPS, I received a beautiful message of support from a PhD student in physical chemistry and quantum computing named <a href="https://ca.linkedin.com/in/karen-morenz-189310112">Karen Morenz</a>. Besides her strong words of encouragement, Karen wanted to share with me an <a href="https://medium.com/@kjmorenz/is-it-really-just-sexism-an-alternative-argument-for-why-women-leave-stem-cccdf066d8b1">essay</a> she had written on Medium about why too many women leave STEM.</p> <p>Karen&#8217;s essay, I found, marshaled data, logic, and her own experience in support of an insight that strikes me as true and important and underappreciated&#8212;one that dovetails with what I&#8217;ve heard from many other women in STEM fields, including my wife <a href="https://www.cs.utexas.edu/~danama/">Dana</a>. So I asked Karen for permission to reprint her essay on this blog, and she graciously agreed.</p> <p>Briefly: anyone with a brain and a soul wants there to be many more women in STEM. Karen outlines a realistic way to achieve this shared goal. Crucially, Karen&#8217;s way is <em>not</em> about shaming male STEM nerds for their deep-seated misogyny, their arrogant mansplaining, or their gross, creepy, predatory sexual desires. Yes, you can go the shaming route (God knows it&#8217;s being tried). If you do, you&#8217;ll probably snare many guys who really do deserve to be shamed as creeps or misogynists, along with many more who don&#8217;t. Yet for all your efforts, Karen predicts, you&#8217;ll no more solve the original problem of too few women in STEM, than arresting the kulaks solved the problem of lifting the masses out of poverty.</p> <p>For you still won&#8217;t have made a dent in the real issue: namely that, the way we&#8217;ve set things up, pursuing an academic STEM career demands fanatical devotion, to the exclusion of nearly everything else in life, between the ages of roughly 18 and 35. And as long as that&#8217;s true, Karen says, the majority of talented women are going to look at academic STEM, in light of all the other great options available to them, and say &#8220;no thanks.&#8221; Solving this problem might look like more money for maternity leave and childcare. It might also look like re-imagining the academic career trajectory itself, to make it easier to rejoin it after five or ten years away. Way back in 2006, I tried to make this point in a blog post called <a href="https://www.scottaaronson.com/blog/?p=87">Nerdify the world, and the women will follow</a>. I&#8217;m grateful to Karen for making it more cogently than I did.</p> <p>Without further ado, here&#8217;s Karen&#8217;s essay. &#8211;SA</p> <h3><strong>Is it really just sexism? An alternative argument for why women leave STEM</strong></h3> <p>by Karen Morenz</p> <p>Everyone knows that you’re not supposed to start your argument with ‘everyone knows,’ but in this case, I think we ought to make an exception:</p> <p>Everyone knows that STEM (Science, Technology, Engineering and Mathematics) has a problem retaining women (see, for example&nbsp;<a href="https://www.researchgate.net/publication/283809613_Women_in_STEM_Family-Related_Challenges_and_Initiatives" target="_blank" rel="noreferrer noopener">Jean, Payne, and Thompson 2015</a>). We pour money into attracting girls and women to STEM fields. We pour money into recruiting women, training women, and addressing sexism, both overt and subconscious.&nbsp;<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5491652/" target="_blank" rel="noreferrer noopener">In 2011</a>, the United States spent nearly $3 billion tax dollars on STEM education, of which roughly one third was spent supporting and encouraging underrepresented groups to enter STEM (including women). And yet, women are still leaving at alarming rates.</p> <p>Alarming? Isn’t that a little, I don’t know, alarmist? Well,&nbsp;<strong>let’s look at some stats.</strong></p> <p>A recent report by the&nbsp;<a rel="noreferrer noopener" href="https://journals.sagepub.com/doi/full/10.1177/0894845313483003#" target="_blank">National Science Foundation (2011)</a>&nbsp;found that women received 20.3% of the bachelor’s degrees and 18.6% of the PhD degrees in physics in 2008. In chemistry, women earned 49.95% of the bachelor’s degrees but only 36.1% of the doctoral degrees. By comparison, in biology women received 59.8% of the bachelor’s degrees and 50.6% of the doctoral degrees. A&nbsp;<a rel="noreferrer noopener" href="https://cen.acs.org/articles/96/i10/why-cant-the-drug-industry-solve-its-gender-diversity-problem.html" target="_blank">recent article</a>&nbsp;in Chemical and Engineering News showed a chart based on a survey of life sciences workers by Liftstream and MassBio demonstrating how women are vastly underrepresented in science leadership despite earning degrees at similar rates, which I’ve copied below. The story is the same in academia, as you can see on the&nbsp;<a rel="noreferrer noopener" href="https://eige.europa.eu/sites/default/files/garcia_working_paper_5_academic_careers_gender_inequality.pdf" target="_blank">second chart</a>&nbsp;— from comparable or even larger number of women at the student level, we move towards a significantly larger proportion of men at the more and more advanced stages of an academic career.</p> <figure class="wp-block-image"><img src="https://miro.medium.com/max/700/1*X0Pt4nHwU9JiVN0RDyb1sQ.png" alt=""/></figure> <figure class="wp-block-image"><img src="https://miro.medium.com/max/697/1*vx6M8mBvhk0pYtNq3B06fg.png" alt=""/></figure> <p>Although 74% of women in STEM&nbsp;<a rel="noreferrer noopener" href="http://www.ncwit.org/sites/default/files/legacy/pdf/NCWIT_TheFacts_rev2010.pdf" target="_blank">report</a>&nbsp;“loving their work,” half (56%, in fact) leave over the course of their career — largely at the “mid-level” point, when the loss of their talent is most costly as they have just completed training and begun to contribute maximally to the work force.</p> <p><a href="https://arxiv.org/abs/1810.01511" target="_blank" rel="noreferrer noopener">A study by Dr. Flaherty</a>&nbsp;found that women who obtain faculty position in astronomy spent on average 1 year less than their male counterparts between completing their PhD and obtaining their position — but he concluded that this is because&nbsp;<strong>women leave the field at a rate 3 to 4 times greater than men</strong>, and in particular, if they do not obtain a faculty position quickly, will simply move to another career. So, women and men are hired at about the same rate during the early years of their post docs, but women stop applying to academic positions and drop out of the field as time goes on, pulling down the average time to hiring for women.</p> <p>There are many more studies to this effect. At this point,&nbsp;<strong>the assertion that women leave STEM at an alarming rate after obtaining PhDs is nothing short of an established fact</strong>. In fact, it’s actually a problem across all academic disciplines, as you can see in&nbsp;<a rel="noreferrer noopener" href="http://blogs.nature.com/news/2012/11/leaky-pipelines-for-canadian-women-in-research.html" target="_blank">this matching chart</a>&nbsp;showing the same phenomenon in humanities, social sciences, and education. The phenomenon has been affectionately dubbed the “leaky pipeline.”</p> <figure class="wp-block-image"><img src="https://miro.medium.com/max/571/0*koOEWDCY2BBSvZCN" alt=""/></figure> <p><strong>But hang on a second, maybe there just aren’t enough women qualified for the top levels of STEM? Maybe it’ll all get better in a few years if we just wait around doing nothing?</strong></p> <p>Nope, sorry. This&nbsp;<a href="http://www.pewsocialtrends.org/2018/01/09/women-and-men-in-stem-often-at-odds-over-workplace-equity/" target="_blank" rel="noreferrer noopener">study</a>&nbsp;says that 41% of highly qualified STEM people are female. And also, it’s clear from the previous charts and stats that a significantly larger number of women are getting PhDs than going on the be professors, in comparison to their male counterparts.&nbsp;<a href="https://cen.acs.org/articles/96/i10/why-cant-the-drug-industry-solve-its-gender-diversity-problem.html" target="_blank" rel="noreferrer noopener">Dr. Laurie Glimcher</a>, when she started her professorship at Harvard University in the early 1980s, remembers seeing very few women in leadership positions. “I thought, ‘Oh, this is really going to change dramatically,’ ” she says. But 30 years later, “it’s not where I expected it to be.” Her experiences are similar to those of other leading female faculty.</p> <p><strong>So what gives? Why are all the STEM women leaving?</strong></p> <p>It is widely believed that sexism is the leading problem. A quick google search of “sexism in STEM” will turn up a veritable cornucopia of articles to that effect. And indeed, around 60% of women report experiencing some form of sexism in the last year (<a href="https://journals.sagepub.com/doi/pdf/10.1177/0361684315596162" target="_blank" rel="noreferrer noopener">Robnett 2016</a>). So, that’s clearly not good.</p> <p>And yet, if you ask leading women researchers like Nobel Laureate in Physics 2018, Professor Donna Strickland, or Canada Research Chair in Advanced Functional Materials (Chemistry), Professor Eugenia Kumacheva,&nbsp;<a href="https://www.bbc.co.uk/sounds/play/p06mrmnt" target="_blank" rel="noreferrer noopener">they</a>&nbsp;<a href="https://www.intermissionmagazine.ca/features/the-scientist-and-the-artist-conversations-with-eugenia-kumacheva-and-fiona-reid/" target="_blank" rel="noreferrer noopener">say</a>&nbsp;that sexism was not a barrier in their careers. Moreover, extensive research has shown that sexism has overall decreased since Professors Strickland and Kumacheva (for example) were starting their careers. Even more interestingly,&nbsp;<a href="https://journals.sagepub.com/doi/pdf/10.1177/0361684315596162" target="_blank" rel="noreferrer noopener">Dr. Rachael Robnett showed</a>&nbsp;that more mathematical fields such as Physics have a greater problem with sexism than less mathematical fields, such as Chemistry, a finding which rings true with the subjective experience of many women I know in Chemistry and Physics. However, as we saw above, women leave the field of Chemistry in greater proportions following their BSc than they leave Physics. On top of that, although 22% of women&nbsp;<a href="http://www.pewsocialtrends.org/2018/01/09/women-and-men-in-stem-often-at-odds-over-workplace-equity/" target="_blank" rel="noreferrer noopener">report</a>&nbsp;experiencing sexual harassment at work, the proportion is the same among STEM and non-STEM careers, and yet women leave STEM careers at a much higher rate than non-STEM careers.</p> <p>So,it seems that<strong>&nbsp;sexism can not fully explain why women with STEM PhDs are leaving STEM</strong>. At the point when women have earned a PhD, for the most part they have already survived the worst of the sexism. They’ve already proven themselves to be generally thick-skinned and, as anyone with a PhD can attest, very stubborn in the face of overwhelming difficulties. Sexism is frustrating, and it can limit advancement, but it doesn’t fully explain why we have so many women obtaining PhDs in STEM, and then leaving. In fact, at least in the U of T chemistry department, faculty hires are directly proportional to the applicant pool —although the exact number of applicants are not made public, from public information we can see that approximately one in four interview invitees are women, and approximately one in four hires are women. Our hiring committees have received bias training, and it seems that it has been largely successful. That’s not to say that we’re done, but it’s time to start looking elsewhere to explain why there are so few women sticking around.</p> <p><strong>So why don’t more women apply?</strong></p> <p>Well,&nbsp;<a href="https://www.theguardian.com/science/2015/dec/14/many-women-in-stem-fields-expect-to-quit-within-five-years-survey-finds" target="_blank" rel="noreferrer noopener">one truly brilliant researcher</a>&nbsp;had the groundbreaking idea of asking women why they left the field. When you ask women why they left, the number one reason they cite is<strong>&nbsp;balancing work/life responsibilities</strong>&nbsp;— which as far as I can tell is a euphemism for family concerns.</p> <p><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5315093/#FN2" target="_blank" rel="noreferrer noopener">The</a>&nbsp;<a href="http://www.ncwit.org/sites/default/files/legacy/pdf/NCWIT_TheFacts_rev2010.pdf" target="_blank" rel="noreferrer noopener">research</a>&nbsp;<a href="http://blogs.nature.com/news/2012/11/leaky-pipelines-for-canadian-women-in-research.html" target="_blank" rel="noreferrer noopener">is in</a>&nbsp;<a href="http://www.pewsocialtrends.org/2018/01/09/women-and-men-in-stem-often-at-odds-over-workplace-equity/" target="_blank" rel="noreferrer noopener">on</a>&nbsp;<a href="https://eige.europa.eu/sites/default/files/garcia_working_paper_5_academic_careers_gender_inequality.pdf" target="_blank" rel="noreferrer noopener">this</a>. Women who stay in academia expect to marry later, and delay or completely forego having children, and if they do have children, plan to have fewer than their non-STEM counterparts (<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5315093/#FN2" target="_blank" rel="noreferrer noopener">Sassler et al 2016</a>,&nbsp;<a href="http://blogs.nature.com/news/2012/11/leaky-pipelines-for-canadian-women-in-research.html" target="_blank" rel="noreferrer noopener">Owens 2012</a>). Men in STEM have no such difference compared to their non-STEM counterparts; they marry and have children about the same ages and rates as their non-STEM counterparts (<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5315093/#FN2" target="_blank" rel="noreferrer noopener">Sassler et al 2016</a>). Women leave STEM in droves in their early to mid thirties (<a href="http://www.pewsocialtrends.org/2018/01/09/women-and-men-in-stem-often-at-odds-over-workplace-equity/" target="_blank" rel="noreferrer noopener">Funk and Parker 2018</a>) — the time when women’s fertility begins to decrease, and risks of childbirth complications begin to skyrocket for both mother and child. Men don’t see an effect on their fertility until their mid forties. Of the 56% of women who leave STEM, 50% wind up self-employed or using their training in a not for profit or government, 30% leave to a non-STEM more ‘family friendly’ career, and 20% leave to be stay-at-home moms (<a href="http://www.ncwit.org/sites/default/files/legacy/pdf/NCWIT_TheFacts_rev2010.pdf" target="_blank" rel="noreferrer noopener">Ashcraft and Blithe 2002</a>). Meanwhile, institutions with better childcare and maternity leave policies have twice(!) the number of female faculty in STEM (<a href="https://www.theguardian.com/education/2018/jan/21/better-maternity-leave-could-help-universities-retain-women-study" target="_blank" rel="noreferrer noopener">Troeger 2018</a>). In analogy to the affectionately named “leaky pipeline,” the challenge of balancing motherhood and career has been titled the “maternal wall.”</p> <p><strong>To understand the so-called maternal wall better, let’s take a quick look at the sketch of a typical academic career.</strong></p> <p>For the sake of this exercise, let’s all pretend to be me. I’m a talented 25 year old PhD candidate studying Physical Chemistry — I use laser spectroscopy to try to understand atypical energy transfer processes in innovative materials that I hope will one day be used to make vastly more efficient solar panels. I got my BSc in Chemistry and Mathematics at the age of 22, and have published 4 scientific papers in two different fields already (Astrophysics and Environmental Chemistry). I’ve got a big scholarship, and a lot of people supporting me to give me the best shot at an academic career — a career I dearly want. But, I also want a family — maybe two or three kids. Here’s what I can expect if I pursue an academic career:</p> <p>With any luck, 2–3 years from now I’ll graduate with a PhD, at the age of 27. Academics are expected to travel a lot, and to move a lot, especially in their 20s and early 30s — all of the key childbearing years. I’m planning to go on exchange next year, and then the year after that I’ll need to work hard to wrap up research, write a thesis, and travel to several conferences to showcase my work. After I finish my PhD, I’ll need to undertake one or two post doctoral fellowships, lasting one or two years each, probably in completely different places. During that time, I’ll start to apply for professorships. In order to do this, I’ll travel around to conferences to advertise my work and to meet important leaders in my field, and then, if I am invited for interviews, I’ll travel around to different universities for two or three days at a time to undertake these interviews. This usually occurs in a person’s early 30s — our helpful astronomy guy, Dr. Flaherty, found the average time to hiring was 5 years, so let’s say I’m 32 at this point. If offered a position, I’ll spend the next year or two renovating and building a lab, buying equipment, recruiting talented graduate students, and designing and teaching courses. People work really, really hard during this time and have essentially no leisure time. Now I’m 34. Within usually 5 years I’ll need to apply for tenure. This means that by the time I’m 36, I’ll need to be making significant contributions in my field, and then in the final year before applying for tenure, I will once more need to travel to many conferences to promote my work, in order to secure tenure — if I fail to do so, my position at the university would probably be terminated.&nbsp;<strong>Although many universities offer a “tenure extension” in cases where an assistant professor has had a child, this does not solve all of the problems.&nbsp;</strong>Taking a year off during that critical 5 or 6 year period often means that the research “goes bad” — students flounder, projects that were promising get “scooped” by competitors at other institutions, and sometimes, in biology and chemistry especially, experiments literally go bad. You wind up needing to rebuild much more than just a year’s worth of effort.</p> <p>At no point during this time do I appear stable enough, career-wise, to take even six months off to be pregnant and care for a newborn. Hypothetical future-me is travelling around, or even moving, conducting and promoting my own independent research and training students. As you’re likely aware, very pregnant people and newborns don’t travel well. And academia has a very individualistic and meritocratic culture. Starting at the graduate level, huge emphasis is based on independent research, and independent contributions, rather than valuing team efforts. This feature of academia is both a blessing and a curse. The individualistic culture means that people have the independence and the freedom to pursue whatever research interests them — in fact this is the main draw for me personally. But it also means that there is often no one to fall back on when you need extra support, and because of biological constraints, this winds up impacting women more than men.</p> <p>At this point, I need to make sure that you’re aware of some basics of female reproductive biology. According to Wikipedia, the unquestionable source of all reliable knowledge, at age 25, my risk of conceiving a baby with chromosomal abnormalities (including Down’s Syndrome) is 1 in about 1400. By 35, that risk more than quadruples to 1 in 340. At 30, I have a 75% chance of a successful birth in one year, but by 35 it has dropped to 66%, and by 40 it’s down to 44%. Meanwhile, 87 to 94% of women report at least 1 health problem immediately after birth, and 1.5% of mothers have a severe health problem, while 31% have long-term persistent health problems as a result of pregnancy (defined as lasting more than six months after delivery). Furthermore, mothers over the age of 35 are at higher risk for pregnancy complications like preterm delivery, hypertension, superimposed preeclampsia, severe preeclampsia (<a rel="noreferrer noopener" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4418963/" target="_blank">Cavazos-Rehg et al 2016</a>). Because of factors like these, pregnancies in women over 35 are known as “geriatric pregnancies” due to the drastically increased risk of complications. This tight timeline for births is often called the “biological clock” — if women want a family, they basically need to start before 35. Now, that’s not to say it’s impossible to have a child later on, and in fact some studies show that it has positive impacts on the child’s mental health. But it is riskier.</p> <figure class="wp-block-image"><img Nerd Interest Obviously I'm Not Defending Aaronson Scott What's MER? A new way to measure quantum materials https://www.sciencedaily.com/releases/2020/01/200116121852.htm Quantum Computers News -- ScienceDaily urn:uuid:52a4fdcb-86da-47b2-43fc-b32d88a18361 Thu, 16 Jan 2020 17:18:52 +0000 Experimental physicists have combined several measurements of quantum materials into one in their ongoing quest to learn more about manipulating and controlling the behavior of them for possible applications. They even coined a term for it -- magneto-elastoresistance, or MER. Quantum physics: Controlled experiment observes self-organized criticality https://www.sciencedaily.com/releases/2020/01/200116121828.htm Quantum Computers News -- ScienceDaily urn:uuid:f91cb23b-c019-2e84-7751-feecbf475369 Thu, 16 Jan 2020 17:18:28 +0000 Researchers have observed important characteristics of complex systems in a lab experiment. Their discovery could facilitate the development of quantum technologies. AlphaZero learns to rule the quantum world https://www.sciencedaily.com/releases/2020/01/200116101203.htm Quantum Computers News -- ScienceDaily urn:uuid:a2b721ad-ad1d-3305-af26-053f464b867e Thu, 16 Jan 2020 15:12:03 +0000 The chess world was amazed when the computer algorithm AlphaZero learned, after just four hours on its own, to beat the best chess programs built on human expertise. Now a research group has used the very same algorithm to control a quantum computer. Electron spins in slowly moving quantum dots may be controlled by electric fields https://www.sciencedaily.com/releases/2020/01/200115130428.htm Quantum Computers News -- ScienceDaily urn:uuid:4fba1ea7-3938-cbdd-a6ae-b199675b23bc Wed, 15 Jan 2020 18:04:28 +0000 A new article presents a theoretical analysis of electron spins in moving semiconductor quantum dots, showing how these can be controlled by electric fields in a way that suggests they may be usable as information storage and processing components of quantum computers. Colloidal quantum dot laser diodes are just around the corner https://www.sciencedaily.com/releases/2020/01/200114125921.htm Quantum Computers News -- ScienceDaily urn:uuid:c1fa76cf-ed6d-70e4-820a-5fb8183da216 Tue, 14 Jan 2020 17:59:21 +0000 Scientists have incorporated meticulously engineered colloidal quantum dots into a new type of light emitting diodes (LEDs) containing an integrated optical resonator, which allows them to function as lasers. These novel, dual-function devices clear the path towards versatile, manufacturing-friendly laser diodes. The technology can potentially revolutionize numerous fields from photonics and optoelectronics to chemical sensing and medical diagnostics. MIP*=RE https://www.scottaaronson.com/blog/?p=4512 Shtetl-Optimized urn:uuid:6e83ebc3-a380-c9fa-d356-a3fd3d3d681c Tue, 14 Jan 2020 16:59:21 +0000 Here&#8217;s the paper, which weighs in at 165 pages. The authors are Zhengfeng Ji, Anand Natarajan, my former postdoc Thomas Vidick, John Wright (who will be joining the CS faculty at UT Austin this fall), and my wife&#8217;s former student Henry Yuen. Rather than pretending that I can provide intelligent commentary on this opus in [&#8230;] <p><a href="https://arxiv.org/abs/2001.04383">Here&#8217;s the paper</a>, which weighs in at 165 pages. The authors are Zhengfeng Ji, Anand Natarajan, my former postdoc Thomas Vidick, John Wright (who will be joining the CS faculty at UT Austin this fall), and my wife&#8217;s former student Henry Yuen. Rather than pretending that I can provide intelligent commentary on this opus in the space of a day, I&#8217;ll basically just open my comment section to discussion and quote the abstract:</p> <blockquote class="wp-block-quote"><p>We show that the class MIP* of languages that can be decided by a classical verifier interacting with multiple all-powerful quantum provers sharing entanglement is equal to the class RE of recursively enumerable languages. Our proof builds upon the quantum low-degree test of (Natarajan and Vidick, FOCS 2018) by integrating recent developments from (Natarajan and Wright, FOCS 2019) and combining them with the recursive compression framework of (Fitzsimons et al., STOC 2019).<br>An immediate byproduct of our result is that there is an efficient reduction from the Halting Problem to the problem of deciding whether a two-player nonlocal game has entangled value 1 or at most 1/2. Using a known connection, undecidability of the entangled value implies a negative answer to Tsirelson&#8217;s problem: we show, by providing an explicit example, that the closure <em>C<sub>qa</sub></em> of the set of quantum tensor product correlations is strictly included in the set <em>C<sub>qc</sub></em> of quantum commuting correlations. Following work of (Fritz, Rev. Math. Phys. 2012) and (Junge et al., J. Math. Phys. 2011) our results provide a refutation of Connes&#8217; embedding conjecture from the theory of von Neumann algebras. </p></blockquote> <p>I can remember when the class MIP* was first defined and studied, back around 2003, and people made the point that we didn&#8217;t know any reasonable upper bound on the class&#8217;s power&#8212;not NEXP, not NEEEEXP, not even the set of all computable languages. Back then, the joke was how far our <em>proof techniques</em> were from what was self-evidently the truth. I don&#8217;t remember a single person who seriously contemplated that two entangled provers could convince a polynomial-time verifier than an arbitrary Turing machine halts.</p> <p>Still, ever since Natarajan and Wright&#8217;s <a href="https://www.quantamagazine.org/computer-scientists-expand-the-frontier-of-verifiable-knowledge-20190523/">NEEXP in MIP*</a> breakthrough last year, all of us in quantum computing theory knew that MIP*=RE was a live possibility&#8212;and through the summer and fall, I had heard hints that this was imminent.</p> <p>The usual proviso applies: when I&#8217;ve blogged about preprints with amazing new results, most have stood, but at least two ended up being retracted. Still, assuming this one stands (as I&#8217;m guessing it will), I regard it as <em>easily</em> one of the biggest complexity-theoretic surprises so far in this century. Huge congratulations to the authors on what looks to be a historic achievement.</p> <p>In unrelated news, for anyone for whom the 165-page MIP* paper is too heavy going (really??), please enjoy this <a href="https://www.youtube.com/watch?v=u1XXjWr5frE">CNBC video on quantum computing</a>, which features several clips of yours truly speaking in front of a fake UT tower.</p> Complexity Quantum Scott How to verify that quantum chips are computing correctly https://news.mit.edu/2020/verify-quantum-chips-computing-0113 MIT News - Quantum computing urn:uuid:fcdd95a0-bb93-a846-ed78-3a1313144100 Mon, 13 Jan 2020 15:59:03 +0000 A new method determines whether circuits are accurately executing complex operations that classical computers can’t tackle. <p>In a step toward practical quantum computing, researchers from MIT, Google, and elsewhere have designed a system that can verify when quantum chips have accurately performed complex computations that classical computers can’t.</p> <p>Quantum chips perform computations using quantum bits, called “qubits,” that can represent the two states corresponding to classic binary bits — a 0 or 1 — or a “quantum superposition” of both states simultaneously. The unique superposition state can enable quantum computers to solve problems that are practically impossible for classical computers, potentially spurring breakthroughs in material design, drug discovery, and machine learning, among other applications.</p> <p>Full-scale quantum computers will require millions of qubits, which isn’t yet feasible. In the past few years, researchers have started developing “Noisy Intermediate Scale Quantum” (NISQ) chips, which contain around 50 to 100 qubits. That’s just enough to demonstrate “quantum advantage,” meaning the NISQ chip can solve certain algorithms that are intractable for classical computers. Verifying that the chips performed operations as expected, however, can be very inefficient. The chip’s outputs can look entirely random, so it takes a long time to simulate steps to determine if everything went according to plan.</p> <p>In a paper published today in <em>Nature Physics</em>, the researchers describe a novel protocol to efficiently verify that an NISQ chip has performed all the right quantum operations. They validated their protocol on a notoriously difficult quantum problem running on custom quantum photonic chip.</p> <p>“As rapid advances in industry and academia bring us to the cusp of quantum machines that can outperform classical machines, the task of quantum verification becomes time critical,” says first author Jacques Carolan, a postdoc in the Department of Electrical Engineering and Computer Science (EECS) and the Research Laboratory of Electronics (RLE). “Our technique provides an important tool for verifying a broad class of quantum systems. Because if I invest billions of dollars to build a quantum chip, it sure better do something interesting.”</p> <p>Joining Carolan on the paper are researchers from EECS and RLE at MIT, as well from the Google Quantum AI Laboratory, Elenion Technologies, Lightmatter, and Zapata Computing. &nbsp;</p> <p><strong>Divide and conquer</strong></p> <p>The researchers’ work essentially traces an output quantum state generated by the quantum circuit back to a known input state. Doing so reveals which circuit operations were performed on the input to produce the output. Those operations should always match what researchers programmed. If not, the researchers can use the information to pinpoint where things went wrong on the chip.</p> <p>At the core of the new protocol, called “Variational Quantum Unsampling,” lies a “divide and conquer” approach, Carolan says, that breaks the output quantum state into chunks. “Instead of doing the whole thing in one shot, which takes a very long time, we do this unscrambling layer by layer. This allows us to break the problem up to tackle it in a more efficient way,” Carolan says.</p> <p>For this, the researchers took inspiration from neural networks — which solve problems through many layers of computation —&nbsp;to build a novel “quantum neural network” (QNN), where each layer represents a set of quantum operations.</p> <p>To run the QNN, they used traditional silicon fabrication techniques to build a 2-by-5-millimeter NISQ chip with more than 170 control parameters — tunable circuit components that make manipulating the photon path easier. Pairs of photons are generated at specific wavelengths from an external component and injected into the chip. The photons travel through the chip’s phase shifters — which change the path of the photons — interfering with each other. This produces a random quantum output state —&nbsp;which represents what would happen during computation. The output is measured by an array of external photodetector sensors.</p> <p>That output is sent to the QNN. The first layer uses complex optimization techniques to dig through the noisy output to pinpoint the signature of a single photon among all those scrambled together. Then, it “unscrambles” that single photon from the group to identify what circuit operations return it to its known input state. Those operations should match exactly the circuit’s specific design for the task. All subsequent layers do the same computation — removing from the equation any previously unscrambled photons — until all photons are unscrambled.</p> <p>As an example, say the input state of qubits fed into the processor was all zeroes. The NISQ chip executes a bunch of operations on the qubits to generate a massive, seemingly randomly changing number as output. (An output number will constantly be changing as it’s in a quantum superposition.) The QNN selects chunks of that massive number. Then, layer by layer, it determines which operations revert each qubit back down to its input state of zero. If any operations are different from the original planned operations, then something has gone awry. Researchers can inspect any mismatches between the expected output to input states, and use that information to tweak the circuit design.</p> <p><strong>Boson “unsampling”</strong></p> <p>In experiments, the team successfully ran a popular computational task used to demonstrate quantum advantage, called “boson sampling,” which is usually performed on photonic chips. In this exercise, phase shifters and other optical components will manipulate and convert a set of input photons into a different quantum superposition of output photons. Ultimately, the task is to calculate the probability that a certain input state will match a certain output state. That will essentially be a sample from some probability distribution.</p> <p>But it’s nearly impossible for classical computers to compute those samples, due to the unpredictable behavior of photons. It’s been theorized that NISQ chips can compute them fairly quickly. Until now, however, there’s been no way to verify that quickly and easily, because of the complexity involved with the NISQ operations and the task itself.</p> <p>“The very same properties which give these chips quantum computational power makes them nearly impossible to verify,” Carolan says.</p> <p>In experiments, the researchers were able to “unsample” two photons that had run through the boson sampling problem on their custom NISQ chip — and in a fraction of time it would take traditional verification approaches.</p> <p>“This is an excellent paper that employs a nonlinear quantum neural network to learn the unknown unitary operation performed by a black box,” says Stefano Pirandola, a professor of computer science who specializes in quantum technologies at the University of York. “It is clear that this scheme could be very useful to verify the actual gates that are performed by a quantum circuit — [for example] by a NISQ processor. From this point of view, the scheme serves as an important benchmarking tool for future quantum engineers. The idea was remarkably implemented on a photonic quantum chip.”</p> <p>While the method was designed for quantum verification purposes, it could also help capture useful physical properties, Carolan says. For instance, certain molecules when excited will vibrate, then emit photons based on these vibrations. By injecting these photons into a photonic chip, Carolan says, the unscrambling technique could be used to discover information about the quantum dynamics of those molecules to aid in bioengineering molecular design. It could also be used to unscramble photons carrying quantum information that have accumulated noise by passing through turbulent spaces or materials. &nbsp;</p> <p>“The dream is to apply this to interesting problems in the physical world,” Carolan says.</p> Rob Matheson | MIT News Office Researchers from MIT, Google, and elsewhere have designed a novel method for verifying when quantum processors have accurately performed complex computations that classical computers can’t. They validate their method on a custom system (pictured) that’s able to capture how accurately a photonic chip (“PNP”) computed a notoriously difficult quantum problem. Image: Mihika Prabhu France Unveils Proposed National Strategy for Quantum Technologies https://quantumcomputingreport.com/news/france-unveils-proposed-national-strategy-for-quantum-technologies/ Quantum Computing Report urn:uuid:3cd6c680-4002-e403-a8bc-0b342132d67d Sat, 11 Jan 2020 19:52:03 +0000 After several months of hearings in 2019, French Parliament member Paula Forteza has presented a plan to structure a national strategy for quantum technologies. In reviewing the significant investments that have already been started in the United States, United Kingdom, China, Canada, Australia and other countries, France does not want to be left behind. The [...] <p>After several months of hearings in 2019, French Parliament member Paula Forteza has presented a plan to structure a national strategy for quantum technologies. In reviewing the significant investments that have already been started in the United States, United Kingdom, China, Canada, Australia and other countries, France does not want to be left behind. The 68 page plan, with the title <a href="https://forteza.fr/wp-content/uploads/2020/01/A5_Rapport-quantique-public-BD.pdf">&#8220;Quantum: the technological turn that France will not miss&#8221;</a> calls for an investment of 1.4 billion Euros over five years from sources including the public sector, private sector, local governments, and European Union support. Other key elements of the plan include:</p> <ul><li>Listing of 37 specific proposal (shown below)</li><li>Formation of 20 exploratory projects with annual budgets of up to 10 million Euros per year</li><li>Creation of 3 Centers of Excellence</li><li>Launch of 50 quantum startups by 2024</li><li>Establishment of a late stage investment fund of 300 to 500 million Euros</li></ul> <p>The full plan has been published in French and you can view it <a href="https://forteza.fr/wp-content/uploads/2020/01/A5_Rapport-quantique-public-BD.pdf">here</a>.&nbsp; We are not aware of an English version available at this time, but we have gone ahead and translated the 37 proposals which have been organized by category and you can see the translations below.</p> <p class="has-large-font-size"><strong>Common proposals for all technologies</strong></p> <p><strong>Proposal 5</strong><br>Renew, from 2021, the calls for projects (AAPR) of the axis &#8220;Quantum Technologies&#8221; of the National Agency for Research (ANR) aiming to finance twenty projects annually exploratory for a global annual envelope of 10 M €.</p> <p><strong>Proposal 6</strong><br>Reinforce the &#8220;Quantum Technologies&#8221; axis of the ANR with a specific annual envelope to finance three projects exploratory targeting priority technological paths identified.</p> <p><strong>Proposal 7</strong><br>Encourage French laboratories and companies to respond to “Quantum Technologies” European flagship calls for projects. </p> <p><strong>Proposal 8</strong><br>Include a priority on quantum technologies in the future PSPC and Innovation Contest calls.</p> <p><strong>Proposal 26</strong><br>Create three &#8220;Hubs&#8221; in Paris, Saclay and Grenoble Quantics ”bringing together researchers in quantum physics, theoretical and applied IT researchers, engineers, industrialists in technological fields, and end users.</p> <p><strong>Proposal 27</strong><br>Integrate an evaluation criterion relating to interdisciplinarity in ANR and BPI calls for collaborative projects.</p> <p><strong>Proposal 28</strong><br>Include 6 ECTS of quantum algorithmics in the top 20 cycles of computer engineers and 6 ECTS in cryptography post-quantum and quantum in cryptography masters.</p> <p><strong>Proposal 29</strong><br>Design training paths with a specialization in engineering and quantum computing and anticipate the growing need for engineers and technicians in the supply chains industrial.</p> <p><strong>Proposal 30</strong><br>Sensitize ecosystem players to the new provisions of the PACTE law relating to the mobility of researchers and access using laboratories by startups.</p> <p><strong>Proposal 31</strong><br>Support the creation of around fifty startups in the quantum until 2024.</p> <p><strong>Proposal 32</strong><br>Create a late-stage investment fund for € 300-500 million trust dedicated to quantum startups.</p> <p><strong>Proposal 33</strong><br>Sensitize the various most strategic players to risks technological looting and the tools available to face it.</p> <p><strong>Proposal 34</strong><br>Identify and monitor strategic assets and activities and deploy, if necessary, the Potential Protection system Scientific and Technological (PPST).</p> <p><strong>Proposal 35</strong><br>Identify areas of cooperation and possible synergies with France&#8217;s international partners in terms of quantum technologies.</p> <p><strong>Proposal 36</strong><br>Establish a Strategic Committee responsible for taking the orientation decisions for research actions.</p> <p><strong>Proposal 37</strong><br>Appoint an interministerial coordinator of the national plan, responsible for ensuring the overall coherence of the actions of different public and private actors at the national level.</p> <p class="has-large-font-size"><strong>Proposals relating to quantum computing</strong></p> <p><strong>Proposal 1</strong><br>Host, at the “Very Large Computing Center” (TGCC), a diversified, scalable and accessible to communities of researchers and developers academic and industrial.</p> <p><strong>Proposal 2</strong><br>Open a permanent call for contributions to French and European startups and laboratories developing quantum acceleration processors for integration to the computing infrastructure.</p> <p><strong>Proposal 3</strong><br>Develop a public-private offer of QCaaS or “Quantum Computing as a Service”competitive.</p> <p><strong>Proposal 9</strong><br>Strengthen Grenoble microelectronic teams with skills in computing software and architectures.</p> <p><strong>Proposal 10</strong><br>Deploy agile project management to reduce gradually uncertainties and costs throughout the project.</p> <p><strong>Proposal 11</strong><br>Deploy, through a PIA and PPR action, an R &amp; D-Capitalization program aimed at developing scalable quantum accelerators.</p> <p><strong>Proposal 12</strong><br>Support, through the AAPR of the &#8220;Quantum Technologies&#8221; axis ANR, a research program aimed at exploring Bold Silicon Ways</p> <p><strong>Proposal 13</strong><br>Set up, in 2019, a Grand Innovation Challenge &#8220;NISQ&#8221; aiming to develop, before 2023, a business software stack interoperable for the chemical, logistics and of AI.</p> <p><strong>Proposal 14</strong><br>Include the Grand Défi in a framework of bilateral collaborations with other European countries.</p> <p><strong>Proposal 15</strong><br>Strengthen research resources in algorithms and software in the field of quantum computing.</p> <p><strong>Proposal 16</strong><br>Set up, in 2022, a Grand Innovation Challenge aimed at develop a complete quantum computing solution, under reserve of convincing intermediate results for the Grand Défi &#8220;NISQ&#8221; and for the PIA action &#8220;quantum accelerators&#8221;.</p> <p><strong>Proposal 17</strong><br>Include specifications for the acquisition of accelerators experimental quantum in certain calls for tenders GENCI relating to the acquisition, renewal and extension of the French supercomputer fleet.</p> <p><strong>Proposal 24</strong><br>Disseminate the use of quantum computing, through &#8220;Challenges&#8221; and “Hackathons” offered by industrialists in the sectors most advanced applications. The “Airbus Quantum Computing Challenge” could be taken as a model.</p> <p class="has-large-font-size"><strong>Proposals relating to quantum sensors</strong></p> <p><strong>Proposal 18</strong><br>Structuring through a succession of i-Lab, i-Nov and PSPC-Région an industrial value chain for the production of diamond-based impurity sensors.</p> <p><strong>Proposal 25</strong><br>Support, through &#8220;Challenges&#8221; offered by application sectors, manufacturers of quantum sensors in looking for outlets in the application sectors.</p> <p class="has-large-font-size"><strong>Proposals relating to cryptography post-quantum and quantum</strong></p> <p><strong>Proposal 4</strong><br>Deploy a test platform for different devices quantum communications.</p> <p><strong>Proposal 19</strong><br>Support, through i-Nov competitions and support systems and accelerating the innovation of the ministries concerned, the development, before 2022, of a competitive offer of post-quantum cryptography for resource systems limited calculation.</p> <p><strong>Proposal 20</strong><br>Develop a strategy for evaluating QKD systems based on the French and European certification scheme.</p> <p><strong>Proposal 21</strong><br>Support, through the AAPR of the &#8220;Quantum Technologies&#8221; axis of the ANR, a research action relating to the maturation of the QKD technology (continuous variable and variable systems discrete, quantum relays, satellite links, etc.) involving quantum communications experts, cybersecurity experts and telecom equipment manufacturers.</p> <p class="has-large-font-size"><strong>Enabling Technology Proposals</strong></p> <p><strong>Proposal 22</strong><br>Support, through the i-Lab competitions, the i-Nov competitions and PSPC projects, the development of a French offer competitive in ultrahigh vacuum and compact cryogenics for temperatures from 1 to 40K.</p> <p><strong>Proposal 23</strong><br>Support, through i-Lab competitions, i-Nov competitions, PSPC projects and support and acceleration devices innovation of the ministries concerned, or an action of the PIA, the development of a competitive French offer in terms of extreme cryogenics for sub-K temperatures.</p> <p class="has-text-align-right has-small-font-size">January 11, 2020</p> dougfinke1 IBM Discusses Quantum Computing Applications and Customers at CES https://quantumcomputingreport.com/news/ibm-discusses-quantum-computing-applications-and-customers-at-ces/ Quantum Computing Report urn:uuid:fa270b41-97dc-47ab-fc69-e819b9ef61cd Thu, 09 Jan 2020 04:58:43 +0000 In a large presentation at today’s CES show, IBM described how they are making progress in acquiring customers and working with them to develop applications that will take advantage of quantum computing.  Highlights of their presentation include: They have expanded their IBM Q Network to include over 100 organizations in industries as far ranging as [...] <p>In a large presentation at today’s CES show, IBM described how they are making progress in acquiring customers and working with them to develop applications that will take advantage of quantum computing.&nbsp; Highlights of their presentation include:</p> <ul><li>They have expanded their IBM Q Network to include over 100 organizations in industries as far ranging as airlines, automotive, banking and finance, energy, insurance, materials and electronics.</li><li>They recently expanded their startup partners in the IBM Q Network by adding five new companies.&nbsp; By our count, <a href="https://quantumcomputingreport.com/scorecards/software-partners/">they now have partnerships with 27 different startup companies</a>.</li><li>They described research efforts with Daimler AG (parent of Mercedes) to use quantum computers to model next generation lithium-sulfur batteries for automobiles.</li><li>They are entering a multi-year collaborative effort with Delta Airlines to explore applications of quantum computing in the airline industry.</li><li>They now have over 200, 000 users of their IBM Q systems who have run hundreds of billions of executions on either the simulator or the actual quantum machines.&nbsp; These users have generated over 200 third-party research papers.</li></ul> <p>Although the current generation of machines may not be quite powerful enough to provide an advantage over the use of a classical computer for commercial applications, it is clear that they are confident they will have more powerful generations of quantum computers in the years ahead that will be able to demonstrate a quantum advantage. So they are taking steps right now to prepare as many customers as possible to utilize quantum computers.&nbsp; As such, IBM is devoting significant resources into marketing and applications as a strategy to recreate the success they had in the 1960’s when they dominated mainframe computing.</p> <p>For more on IBM’s quantum customer announcements, you can view three separate press releases describing their work with <a href="https://newsroom.ibm.com/2020-01-08-Delta-Partners-with-IBM-to-Explore-Quantum-Computing-an-Airline-Industry-First">Delta Airlines</a>, <a href="https://www.ibm.com/blogs/research/2020/01/next-gen-lithium-sulfur-batteries/">Daimler</a>, and <a href="https://newsroom.ibm.com/2020-01-08-IBM-Working-with-Over-100-Organizations-to-Advance-Practical-Quantum-Computing-Signs-New-Collaborations-with-Anthem-Delta-Airlines-Goldman-Sachs-Wells-Fargo-Woodside-Energy-Los-alamos-National-Laboratory-Stanford-University-Georgia-Tech-and-Sta">other organizations</a>.</p> <p class="has-text-align-right has-small-font-size"><amp-fit-text layout="fixed-height" min-font-size="6" max-font-size="72" height="80">January 8, 2020</amp-fit-text></p> dougfinke1 IBM Doubles Their Quantum Volume Performance Metric to 32 https://quantumcomputingreport.com/news/ibm-doubles-their-quantum-volume-performance-metric-to-32/ Quantum Computing Report urn:uuid:1d0cc5c9-a591-bd69-ae3c-9493d1ae3b41 Thu, 09 Jan 2020 01:43:33 +0000 We had previously reported on IBM’s Quantum Volume metric and their goal of achieving a doubling of this measure every year. This factor takes into account a number of factors including qubit count, qubit quality, qubit connectivity, crosstalk considerations and a number of other factors to provide a relative figure of merit for a quantum [...] <p>We had <a href="https://quantumcomputingreport.com/news/ibm-achieves-higher-quantum-volume-with-the-ibm-q-system-one-design/">previously reported</a> on IBM’s <a href="https://arxiv.org/pdf/1811.12926.pdf">Quantum Volume metric</a> and their goal of achieving a doubling of this measure every year. This factor takes into account a number of factors including qubit count, qubit quality, qubit connectivity, crosstalk considerations and a number of other factors to provide a relative figure of merit for a quantum computer design.&nbsp; This metric is technology agnostic and could conceivable be used by other gate level quantum computer developers.</p> <p>In March of 2019, they announced that they had increased this factor to 16 with the announcement of their IBM Q System One.  Now, they have announced they have doubled this once again to 32 with a new 28 qubit design called Raleigh. This design combines the lattice structure of the 53 qubit design (the 28 qubit would appear to look roughly like half of the 53 qubit design) that they introduced last year with additional upgrades implemented in some of the latter versions of the 20 qubit design.</p> <p>Although it might not seem obvious why a 28 qubit part would show a higher metric of their 53 qubit design, the answer is that the Quantum Volume metric assumes a square circuit of <em>m</em> qubits with a depth of <em>m</em> gates.&nbsp; And the limiting factor right now appears to be the gate depth that can be used before the errors become too great.&nbsp; For more on this, you can view IBM’s paper describing the quantum volume metric and measurement methodology <a href="https://arxiv.org/pdf/1811.12926.pdf">here</a>.</p> <p>IBM has prepared a <a href="https://www.ibm.com/blogs/research/2020/01/quantum-volume-32/">good blog article</a> that describes their generation cycles of learning and plans to provide continued improvement. Among other things they will take some of the advancements created in this 28 qubit design and apply it to subsequent generations of the 53 qubit design.&nbsp; In addition, they have several other improvements ideas generated from their research that they intend to apply in the future to further improve the qubit quality.</p> <p>One thing to mention is that the nature of the Quantum Volume metric is to treat equal importance to the width of the qubits and the gate depth so that both are equal to achieve essentially a square circuit configuration. However, it is not clear how many quantum algorithms are configured this way.&nbsp; Certain algorithms being researched for NISQ applications, such as QAOA, are called “short depth” algorithms where the number of qubits may be significantly larger than the gate depth to minimize the effect of decoherence. For more, you can view IBM’s latest blog describing this new development <a href="https://www.ibm.com/blogs/research/2020/01/quantum-volume-32/">here</a>.</p> <p class="has-text-align-right has-small-font-size">January 8, 2020 </p> dougfinke1 Quantum Machines Announces its Quantum Orchestration Platform https://quantumcomputingreport.com/news/quantum-machines-announces-its-quantum-orchestration-platform/ Quantum Computing Report urn:uuid:980e4527-5212-9809-806c-c83cbe39b3a9 Tue, 07 Jan 2020 22:29:24 +0000 Building a quantum computer requires assembling a lot of different pieces.  This includes the quantum chip, the control electronics and control firmware, mechanical packaging, software, libraries, etc.  The complexity of assembling all these pieces can be a big challenge.  Although a large company like IBM can assemble the diverse set of talent to do all [...] <p>Building a quantum computer requires assembling a lot of different pieces.&nbsp; This includes the quantum chip, the control electronics and control firmware, mechanical packaging, software, libraries, etc.&nbsp; The complexity of assembling all these pieces can be a big challenge.&nbsp; Although a large company like IBM can assemble the diverse set of talent to do all of this, it has been much more difficult for a small startup or even a university research organization to build their own a quantum computer with all the pieces unless they are very well funded.</p> <p>This is where Quantum Machines’ Quantum Orchestration Platform fits in.&nbsp; Although there are many efforts to build quantum chips, the complexity of providing the necessary control electronics and control firmware and software to control the chips can be just as difficult and the expertise to do this may not be as readily available.&nbsp; The Quantum Orchestration Platform provides a solution for those teams that want to bring in this capability from the outside instead of designing it themselves.&nbsp; The diagram below shows where their technology would fit into the stack.</p> <figure class="wp-block-image size-large"><img src="https://secureservercdn.net/" alt="" class="wp-image-6114" srcset="https://secureservercdn.net/ 200w, https://secureservercdn.net/ 300w, https://secureservercdn.net/ 400w, https://secureservercdn.net/ 600w, https://secureservercdn.net/ 768w, https://secureservercdn.net/ 800w, https://secureservercdn.net/ 933w" sizes="(max-width: 933px) 100vw, 933px" /><figcaption>Diagram that Shows Where the Quantum Orchestration Platform Fits In the Stack</figcaption></figure> <p>The platform consists of device called an Analog Front-End &amp; Pulse Processor and associated firmware that can perform all the pulse generation, readout, control flow and classical processing capabilities needed.  Multiple units can be ganged together to provide integrated capability for more channels. Quantum Machines indicates that their platform has been designed with flexibility in mind and can work with many different qubit implementation technologies including superconducting, trapped ions, NV centers, quantum dots, and topological qubits. Quantum Machines has also created their own programming language called Qua for programming the system.</p> <figure class="wp-block-image size-large"><img src="https://secureservercdn.net/" alt="" class="wp-image-6115" srcset="https://secureservercdn.net/ 200w, https://secureservercdn.net/ 300w, https://secureservercdn.net/ 400w, https://secureservercdn.net/ 600w, https://secureservercdn.net/ 768w, https://secureservercdn.net/ 800w, https://secureservercdn.net/ 1017w" sizes="(max-width: 1017px) 100vw, 1017px" /><figcaption><strong>Quantum Machines Analog Front-End &amp; Pulse Processor</strong></figcaption></figure> <p>Although some vendors can supply some of the pieces needed in that critical middle layers of the stack, Quantum Machines product is interesting because they are uniquely providing an integrated hardware and software capability for these middle layers. This will make it easier for organizations to build a quantum computer with the chips they have developed. Quantum Machines indicates that their product is already in use within multiple organizations including multinational corporations, quantum startups, government laboratories, and academic institutions in six countries.  For more details on the Quantum Orchestration Platform, you can visit the Quantum Machines web site <a href="https://www.quantum-machines.co/">here</a>. </p> <p class="has-text-align-right has-small-font-size">January 7, 2020</p> dougfinke1 Indeterminist physics for an open world https://www.sciencedaily.com/releases/2020/01/200107104921.htm Quantum Computers News -- ScienceDaily urn:uuid:04b28039-3ef1-bfcf-b973-e519a03f5061 Tue, 07 Jan 2020 15:49:21 +0000 Classical physics is characterized by the equations describing the world. Yet our day-to-day experience is struck by this deterministic vision of the world. A physicist has been analyzing the classical mathematical language used in modern physics. He has thrown light on a contradiction between the equations that explained the phenomena and the finite world. He suggests making changes to the mathematical language to allow randomness and indeterminism to become part of classical physics. Quantum Computing Outlook for 2020 https://quantumcomputingreport.com/our-take/quantum-computing-outlook-for-2020/ Quantum Computing Report urn:uuid:8a2e70af-1e76-70cf-6ba0-458aa4b362b5 Fri, 03 Jan 2020 16:18:33 +0000 The year 2019 was a busy year in the quantum community with a lot of new developments and announcements.  We are sure that 2020 will be just as busy, if not more so, and expect continued advances.  We have seen some of the roadmaps that folks in the industry have discussed so with our intrepid [...] <p>The year 2019 was a busy year in the quantum community with a lot of new developments and announcements.&nbsp; We are sure that 2020 will be just as busy, if not more so, and expect continued advances.&nbsp; We have seen some of the roadmaps that folks in the industry have discussed so with our intrepid 20/20 vision (pardon the pun!) we will describe some of the developments that we expect to see this year.</p> <p class="has-medium-font-size"><strong><span style="text-decoration: underline;">Hardware</span></strong></p> <p>Hardware providers will continue to make advances in both qubit count, qubit quality and new technologies in 2020.&nbsp; Things we expect to see include:</p> <ul><li>In September 2018, Rigetti announced a new architecture they call Aspen starting with a 16 qubit chip, advancing to an intermediate density of 32 or 64 qubits with a large version of 128 qubits in their roadmap.&nbsp; In December they announced their 32 qubit version, called Aspen-7, which will run on both Rigetti’s QCS as well as Amazon’s Braket cloud services<strong>.&nbsp; In 2020, we expect that they will announce availability of the 128 qubit version on these services too. </strong></li></ul> <ul><li>In October 2019, Google announced that they successfully completed their quantum supremacy experiment with their 53 qubit Sycamore chip.&nbsp; Since then they have hinted at various industry conferences that they are working on a <strong>57+ qubit version</strong> of this chip with some improved qubit quality metrics.&nbsp; We think the reason for the “+” is that the chip may have 59 or 60 qubits in the design, but a few might not work due to mechanical or yield failures.&nbsp; However, they have indicated that a large focus of their 2020 activity will be <strong>to improve the gate fidelities</strong>.&nbsp; In particular, their current Sycamore had an average 0.62% two-qubit simultaneous gate error and they would like to get that down to 0.1%.</li></ul> <ul><li>IBM has publicly declared their intention to double what they call Quantum Volume every year.&nbsp; Qubit Volume is a metric that can provide a general description of a machines power that takes into account the number of qubits, the quality of the qubits and other factors. &nbsp;When they announced their 20 qubit IBM Q System One in 2019 they indicated that they had achieved a Quantum Volume factor of 16 with the design.&nbsp; In September 2019, they announced a 53 qubit machine, but have not yet announced an associated Quantum Volume metric for it. We suspect they are still calibrating it and tuning it up for peak performance and they are waiting until this is done before announcing a quantum volume.&nbsp; In any case, we do expect them to hit a goal of a <strong>doubling of Quantum Volume to 32 in 2020</strong> either with this 53 qubit machine or perhaps something else they may have in development.</li></ul> <ul><li><strong>Another new superconducting entrant in 2020 will be Quantum Circuits Inc. (QCI).</strong>&nbsp; They have announced a partnership with Microsoft that will serve as their cloud provider.&nbsp; Not many details are public about their quantum computer, but we expect to hear more in the coming year. </li></ul> <ul><li>2020 should be a big year for D-Wave with the <strong>production release of their 5000+ qubit Advantage architecture</strong> based upon their <a href="https://quantumcomputingreport.com/news/d-wave-previews-next-generation-quantum-annealing-machine/">Pegasus chip</a>.&nbsp; This architecture should bring substantial improvements in performance due to the increase number of qubits,improved coherence times, and better qubit connectivity.<br><br>We are aware that D-Wave is <a href="https://arxiv.org/abs/1903.06139">working on a technology called nonstoquastic Hamiltonian</a> which allows qubits to be coupled with two degrees of freedom rather than the current one degree of freedom.&nbsp; This technology can substantially improve the problem solving capability of the quantum annealing machines.&nbsp; Although we do not expect this to be included initial in the 2020 Advantage machines, we would expect them to announce a roadmap indicating that this technology will be incorporated in follow-on machines in the 2021-2022 time frame.</li></ul> <ul><li><strong>2020 will see the first public availability of several cloud based ion trap machines from IonQ, Honeywell, and Alpine Quantum Technologies (AQT)</strong>.&nbsp; IonQ and Honeywell will be partnering with Microsoft and AWS to provide cloud access, but it is not yet known if they will also offer their own cloud services. AQT has some interesting possibilities because their ion trap hardware is now programmable via both Google’s Cirq as well as IBM’s Qiskit (see below). </li></ul> <ul><li><strong>We also expect to see cloud availability of photonic technologies from Xanadu.</strong>&nbsp; They use a different type of element called qumodes rather than qubits.&nbsp; Qumodes are continuously variable elements and may have some advantages for certain computations.&nbsp; Xanadu current has a 12 qumode machine in the lab and expect to be offering one with 50+ qumodes by the end of 2020. Another distinguishing feature of photonic technologies is that they do not require the expensive dilution refrigerators that are needed by the other technologies.</li></ul> <ul><li>Another new technology introduction that we expect to see in 2020 is the first cloud based computer based upon spin qubit technology.&nbsp; <strong>QuTech is working on a project called Quantum Inspire and we expect them to announce in 2020 cloud availability of a small quantum machine based on their spin qubit technology.</strong></li></ul> <ul><li>Many other players are working on hardware technologies, but we are not certain how many will be announced in 2020.&nbsp; These include Alibaba (superconducting), Atom Computing (neutral atoms), ColdQuanta (cold atoms), Eeroq (cold atoms), PsiQuantum (photonic), Intel (spin qubits), IQM (superconducting), Microsoft (topological), Silicon Quantum Computing (spin qubits) and several others.&nbsp; <strong>Although we believe most of these efforts will still be in development in 2020, we would not be surprised if one or two announce public availability before the year is out.</strong></li></ul> <p class="has-medium-font-size"><strong><span style="text-decoration: underline;">Cloud Services</span></strong></p> <p>The end of 2019 saw significant announcements from Amazon Web Services (AWS) and Microsoft Azure to provide cloud services for multiple different hardware platforms. We expect to see several additional cloud services announcements in 2020 and we expect to see more of these multi-platform arrangements where a cloud service will support several different hardware platforms including:</p> <ul><li><strong>We expect Google to take steps in 2020 to make their machine more available on the cloud.&nbsp; </strong>Google has their own Google Cloud Services group so we expect them to leverage those capabilities and compete with Microsoft’s Azure and Amazon AWS Braket services.&nbsp; In addition, we note that AQT has also announced it is compatible with Google’s Cirq software so this might provide an alternate platform for Google to support in a cloud platform, if they want.</li></ul> <ul><li>Although Amazon AWS’ initial Braket announcement indicated support for the D-Wave, IonQ, and Rigetti platforms, one additional statement included in the announcement is that <strong>they are expecting to announce additional partners soon</strong>.&nbsp; Their strategy is to develop cross-platform developer tools so that an end user can program using Amazon’s front end can switch between hardware platforms relatively easy. How they intend on doing this will be interesting because each of those platforms are quite different.&nbsp; <strong>There are still a lot of details not yet available about AWS’ Braket offering including pricing, software, and additional details on IonQ’s hardware.</strong>&nbsp; We expect to hear more about these in 2020.</li></ul> <ul><li>Microsoft also announced that their Azure cloud platform will partner with Honeywell, IonQ, and QCI.&nbsp; Their software front end will be the established Q# programming language and the Quantum Development Kit<strong>. Like the AWS announcement a lot of details are still not available including pricing and details on the hardware and we expect to hear more in 2020</strong>.&nbsp; Microsoft also announced that they will eventually hook up their topological based quantum computer to the Azure platform, but we think achieving this in 2020 may be a stretch.</li></ul> <ul><li><strong>IBM has been the most aggressive cloud platform vendor in establishing a dedicated quantum data center in Poughkeepsie, New York.</strong> As of September they had 10 machines quantum machines available on the cloud and were in the process of adding four more.&nbsp; And this does not include their recent announcements to install additional IBM Q System One machines in both Germany and Japan nor does it include any machines that are using for internal research and development.&nbsp; IBM may also opt to provide support for an alternate hardware platform to provide their users a means to compare different technologies.&nbsp; IBM recently announced that their QISKIT software platform now also supports AQT’s ion trap technology and that it only took one week’s work to implement this.&nbsp; We expect that other hardware technologies could be easily supported in QISKIT if IBM chooses to do so. There is also an open source module called <a href="https://quantumcomputingreport.com/news/#FOREST4QISKIT">Forest backend for QISKIT</a>, but we are not sure if IBM is ready to support another superconducting quantum computer. </li></ul> <ul><li><strong>We may see in 2020 even more cloud vendors jump in to provide some form of quantum cloud service.</strong> This could include both classical cloud vendors who don’t want AWS and Azure to get too far ahead of them as well as some of the emerging hardware companies that desire to set up their own cloud service. Also, some application software companies that want to act as resellers and bundle their own application level software with one of the hardware platforms and market both together as a package.</li></ul> <p class="has-medium-font-size"><strong><span style="text-decoration: underline;">Application Software</span></strong></p> <p>In 2019 we saw a bunch of new software startups that are focusing on specific applications and offering their services to end users and we expect this trend to continue in 2020.&nbsp; The focus so far has been working on proof-of-concept applications so that the end users, as well as the startup quantum software companies, can identify specific real world problems and solutions that will prove to be commercially useful when the larger machines are available. <strong>We do expect to see significant development in 2020 in new application libraries, continued enhancements to many of the open source development platforms and improved performance in simulators.</strong> For the gate-based machines, we do not expect to see more than a handful of applications, at best, start being used in a production mode in 2020.&nbsp; In fact, some quantum researchers are not sure there will any significant number of production applications in the NISQ era. They argue that this will not occur until the larger error corrected machines are available later this decade.</p> <p>D-Wave has been working with end users for several years now and over 200 early applications have been developed for their quantum annealing machine.&nbsp; Many of these are proof-of-concept applications that aren’t meant for daily production such as the recent Volkswagen experiment to optimize bus route optimization during the recent Web Summit conference in Lisbon.&nbsp; Because D-Wave started earlier, has a more focused set of potential applications and a larger number of available qubits (even though the qubit quality levels may not be as high as the gate level machines), <strong>we do expect in 2020 to see a handful of these early applications being using on a production basis for commercial use.&nbsp; &nbsp;So on the very important measure of using a quantum computer for commercial use we do expect that D-Wave to beat out the gate level machines, at least in 2020.</strong></p> <p class="has-medium-font-size"><strong><span style="text-decoration: underline;">Optimizing Compilers (aka Transpilers) and Qubit Control Firmware</span></strong></p> <p><strong>Perhaps not as widely appreciated is the importance of the backend compiler and qubit control firmware that translates the application program that user might develop to the specific electronic signals that control the operation of the qubits.</strong> The goal is to execute the user’s program in a way that minimizes qubit and gate count, minimizes circuit depth, and provides the best accuracy for the overall solution.&nbsp; This is accomplished by rearranging the gates that an end user may initially input into something equivalent, but more efficient, as well as optimizing the microwave or laser pulses that control the individual qubits.</p> <p>This software can become enormously complex but is critical to optimizing the performance of the hardware. Google has indicated that they would have been challenged to successfully complete their Quantum Supremacy experience without the use of this software. Leaders in this area include Q-CTRL and Quantum Benchmark, and we have also heard good words about Cambridge Quantum Computing’s (CQC) optimizing compiler for the IBM machines which they claim to be superior to the ones provided by IBM in QISKIT. </p> <p><strong>We expect to see significant developments in this area in 2020.</strong>&nbsp; In December, IBM made one of their machines available for external researcher to experiment with pulse level controls of the hardware.&nbsp; Our belief is that a lot of work still needs to be done in this area with a lot of opportunity to make great strides in this area in 2020.</p> <p class="has-medium-font-size"><strong><span style="text-decoration: underline;">Wish List</span></strong></p> <p>There a few things we would like to see happen in 2020 that would benefit the QC industry overall, but we are not sure how much progress will be made on these in the coming year. Nonetheless, we will list them here to help promote advancements in these areas.</p> <ul><li>Quantum computing nomenclature should be standardized so everyone uses the same terminology.&nbsp; Unfortunately, we see differences in how the same thing is described by different people and this can be quite confusing to a newcomer. (For example, try viewing a collection of different images of a Bloch sphere and you will notice that some versions have switched the positions of the X and Y axes.)</li><li>We would like to see a standardized hardware agnostic programming language for gate level machines with an associated requirement that all higher level software platforms be able to both import and export programs to and from this language.&nbsp; This would encourage interoperability and make it much easier to convert a program from one platform to another.</li><li>With all the new machines coming on-line in 2020 there will be a lot questions about performance benchmarking to compare the different machines.&nbsp; Although IBM has developed their Quantum Volume metric, it is not clear how widely this is supported within the rest of the industry.&nbsp; We’d like to see a standardized benchmark, analogous to LINPACK for supercomputers, that everyone can agree upon to characterize the performance of the quantum computers.</li></ul> <p class="has-medium-font-size"><strong><span style="text-decoration: underline;">Non-Technical Factors</span></strong></p> <p>There are other non-technical factors that we expect to hear more about in 2020.&nbsp; There is a continuing concern that we are not developing a quantum trained workforce as fast as we should. Steps are being taken to improve education and training programs but it is not clear that these are enough. Another factor we see is the growing tension between researchers and government officials over export and visa controls. The researchers are concerned with hampering overall progress in QC research if information cannot flow freely, while the government officials are concerned with maintaining their country’s control over the technology so that it is not use unfairly by a country’s adversary. </p> <p><strong>Finally, there is always talk of a quantum winter.&nbsp; We don’t see that in 2020 as many of the government funding programs that we have reported on will start to kick in.</strong>&nbsp; In addition, there will be continued investment in the private sector, particularly from the large classical computing companies that don’t want to miss out. On a positive note, a few of the smaller software startups have already told us they expect to be profitable in 2020.</p> <p class="has-medium-font-size"><strong><span style="text-decoration: underline;">Summary</span></strong></p> <p><strong>So we expect that 2020 will be another exciting year for the quantum community with a lot of progress being made.</strong> Many of the developments will be extrapolations of things we saw in 2019, but we also expect a few surprises where new technologies or new players come in and provide something new that we did not expect. Still the developments in 2020 will represent continued progress in a technology that will require several decades to reach its full potential.&nbsp; </p> <p>We wish everyone working in this area the best of success and look forward to reporting on your developments as the year progresses.</p> <p class="has-text-align-right has-small-font-size">December 30, 2019</p> Sunil Singh Performance benchmark for quantum computers https://www.sciencedaily.com/releases/2020/01/200102184833.htm Quantum Computers News -- ScienceDaily urn:uuid:566efd5a-6142-0b09-7f32-0291d4de85b3 Thu, 02 Jan 2020 23:48:33 +0000 Researchers have developed a quantum chemistry simulation benchmark to evaluate the performance of quantum devices and guide the development of applications for future quantum computers. Overview https://quantumcomputingreport.com/ Quantum Computing Report urn:uuid:09ee6163-6ba8-29af-4708-3e422875f9ee Mon, 30 Dec 2019 15:29:23 +0000 Sign up here for Quantum Computing Report Alerts to get a notification when there are updates to this web site. In the coming decade, the field of Quantum Computing will undergo a vast transformation from a largely academic endeavor to one with a greater emphasis on commercialization providing real applications, [...] <p><div class="fusion-fullwidth fullwidth-box fusion-builder-row-1 fusion-parallax-none nonhundred-percent-fullwidth non-hundred-percent-height-scrolling" style='background-color: rgba(255,255,255,0);background-image: url("https://secureservercdn.net/");background-position: center center;background-repeat: no-repeat;padding-top:50px;padding-right:0px;padding-bottom:60px;padding-left:0px;-webkit-background-size:cover;-moz-background-size:cover;-o-background-size:cover;background-size:cover;'><div class="fusion-builder-row fusion-row "><div class="fusion-layout-column fusion_builder_column fusion_builder_column_1_1 fusion-builder-column-1 fusion-one-full fusion-column-first fusion-column-last 1_1" style='margin-top:10px;margin-bottom:10px;'> <div class="fusion-column-wrapper" style="padding: 0px 0px 0px 0px;background-position:left top;background-repeat:no-repeat;-webkit-background-size:cover;-moz-background-size:cover;-o-background-size:cover;background-size:cover;" data-bg-url=""> <div class="fusion-text"><h2 class="entry-title" style="text-align: center;" data-fontsize="36" data-lineheight="46"><a href="https://quantumcomputingreport.com/qcr-alerts-signup-form/">Sign up here</a> for Quantum Computing Report Alerts to get a notification when there are updates to this web site.</h2> </div><div class="fusion-clearfix"></div> </div> </div></div></div><div class="fusion-fullwidth fullwidth-box fusion-builder-row-2 nonhundred-percent-fullwidth non-hundred-percent-height-scrolling" style='background-color: rgba(255,255,255,0);background-position: center center;background-repeat: no-repeat;padding-top:40px;padding-right:0px;padding-bottom:30px;padding-left:0px;'><div class="fusion-builder-row fusion-row "><div class="fusion-layout-column fusion_builder_column fusion_builder_column_2_3 fusion-builder-column-2 fusion-two-third fusion-column-first 2_3" style='margin-top:0px;margin-bottom:0px;width:65.3333%; margin-right: 4%;'> <div class="fusion-column-wrapper" style="padding: 0px 0px 0px 0px;background-position:left top;background-repeat:no-repeat;-webkit-background-size:cover;-moz-background-size:cover;-o-background-size:cover;background-size:cover;" data-bg-url=""> <div class="fusion-text"><p>In the coming decade, the field of Quantum Computing will undergo <del></del>a vast transformation from a largely academic endeavor to one with a greater emphasis on commercialization providing real applications, value, and profits to those participating.</p> <p>This website will provide information as this develops and help chronicle and promote Quantum Computing for parties interested in it as a business.  Website material will be aimed at a level in-between a popular press &#8220;gee whiz&#8221; view and a paper written for a PhD that you might read in a technical journal.</p> <p>In the future, we will also provide additional products including in-depth market research reports on various aspects of quantum computing as well as custom consulting services in such areas as business development, product strategy, competitive analysis, due diligence, marketing communications, and sales operations.</p> <p>Inquiries or suggestions can be sent to <a href="mailto:info@quantumcomputingreport.com">info@quantumcomputingreport.com</a>.</p> </div><div class="fusion-clearfix"></div> </div> </div><div class="fusion-layout-column fusion_builder_column fusion_builder_column_1_3 fusion-builder-column-3 fusion-one-third fusion-column-last 1_3" style='margin-top:10px;margin-bottom:10px;width:30.6666%'> <div class="fusion-column-wrapper" style="padding: 0px 0px 0px 0px;background-position:left top;background-repeat:no-repeat;-webkit-background-size:cover;-moz-background-size:cover;-o-background-size:cover;background-size:cover;" data-bg-url=""> <div class="imageframe-align-center"><span class="fusion-imageframe imageframe-none imageframe-1 hover-type-none"><img src="https://secureservercdn.net/" width="211" height="239" alt="" title="Block Sphere Large" class="img-responsive wp-image-292"/></span></div><div class="fusion-clearfix"></div> </div> </div></div></div></p> Sunil Singh Quantum computing motte-and-baileys https://www.scottaaronson.com/blog/?p=4447 Shtetl-Optimized urn:uuid:af340906-1aef-6a55-9029-148b6c73656d Sat, 28 Dec 2019 16:08:12 +0000 In the wake of two culture-war posts&#8212;the first on the term &#8220;quantum supremacy,&#8221; the second on the acronym &#8220;NIPS&#8221;&#8212;it&#8217;s clear that we all need to cool off with something anodyne and uncontroversial. Fortunately, this holiday season, I know just the thing to bring everyone together: groaning about quantum computing hype! When I was at the [&#8230;] <p>In the wake of two culture-war posts&#8212;the <a href="https://www.scottaaronson.com/blog/?p=4450">first</a> on the term &#8220;quantum supremacy,&#8221; the <a href="https://www.scottaaronson.com/blog/?p=4476">second</a> on the acronym &#8220;NIPS&#8221;&#8212;it&#8217;s clear that we all need to cool off with something anodyne and uncontroversial. Fortunately, this holiday season, I know just the thing to bring everyone together: groaning about quantum computing hype!</p> <p>When I was at the <a href="https://q2b.qcware.com/">Q2B conference</a> in San Jose, I learned about lots of cool stuff that&#8217;s happening in the wake of Google&#8217;s quantum supremacy announcement. I heard about the 57-qubit superconducting chip that the Google group is now building, following up on its 53-qubit one; and also about their first small-scale experimental demonstration of my certified randomness protocol. I learned about recent progress on costing out the numbers of qubits and gates needed to do fault-tolerant quantum simulations of useful chemical reactions (IIRC, maybe a hundred thousand qubits and a few hours&#8217; worth of gates&#8212;scary, but not Shor&#8217;s algorithm scary).</p> <p>I also learned about two claims about quantum algorithms that startups have made, and which are being wrongly interpreted. The basic pattern is one that I&#8217;ve come to know well over the years, and which you could call a science version of the <a href="https://philpapers.org/archive/SHATVO-2.pdf">motte-and-bailey</a>. To wit:</p> <ol><li>Startup makes claims that have both a true boring interpretation (e.g., you can do X with a quantum computer), as well as a false exciting interpretation (e.g., you can do X with a quantum computer, <em>and it would actually make sense to do this, because you&#8217;ll get an asymptotic speedup over the best known classical algorithm</em>).</li><li>Lots of business and government people get all excited, because they assume the false exciting interpretation must be true (or why else would everyone be talking about this?). Some of those people ask me for comment.</li><li>I look into it, perhaps by asking the folks at the startup. The startup folks clarify that they meant only the true boring interpretation. To be sure, they&#8217;re actively <em>exploring</em> the false exciting interpretation&#8212;whether some parts of it might be true after all&#8212;but they&#8217;re certainly not making any claims about it that would merit, say, a harsh post on <em>Shtetl-Optimized</em>.</li><li>I&#8217;m satisfied to have gotten to the bottom of things, and I tell the startup folks to go their merry way.</li><li>Yet many people continue to seem as excited as if the false exciting interpretation had been shown to be true. They continue asking me questions that presuppose its truth.</li></ol> <p>Our first instance of this pattern is the <a href="https://www.newscientist.com/article/2227387-quantum-computer-sets-new-record-for-finding-prime-number-factors/">recent claim</a>, by <a href="https://www.zapatacomputing.com/">Zapata Computing</a>, to have set a world record for integer factoring (1,099,551,473,989 = 1,048,589 × 1,048,601) with a quantum computer, by running a QAOA/variational algorithm on IBM&#8217;s superconducting device. Gosh! That sure sounds a lot better than the 21 that&#8217;s been factored with Shor&#8217;s algorithm, doesn&#8217;t it?</p> <p>I read the <a href="https://arxiv.org/abs/1808.08927">Zapata paper</a> that this is based on, entitled &#8220;Variational Quantum Factoring,&#8221; and I don&#8217;t believe that a single word in it is false. My issue is something the paper <em>omits</em>: namely, that once you&#8217;ve reduced factoring to a generic optimization problem, you&#8217;ve thrown away all the mathematical structure that <a href="https://en.wikipedia.org/wiki/Shor%27s_algorithm">Shor&#8217;s algorithm</a> cleverly exploits, and that makes factoring asymptotically easy for a quantum computer. And hence there&#8217;s no reason to expect your quantum algorithm to scale any better than brute-force trial division (or in the most optimistic scenario, trial division enhanced with Grover search). On large numbers, your algorithm will be roundly outperformed even by <em>classical</em> algorithms that do exploit structure, like the <a href="https://en.wikipedia.org/wiki/General_number_field_sieve">Number Field Sieve</a>. Indeed, the quantum computer&#8217;s success at factoring the number will have had little or nothing to do with its being <em>quantum</em> at all&#8212;a classical optimization algorithm would&#8217;ve served as well. And thus, the only reasons to factor a number on a quantum device in this way, would seem to be stuff like calibrating the device.</p> <p>Admittedly, to people who work in quantum algorithms, everything above is so obvious that it doesn&#8217;t need to be said. But I learned at Q2B that there are interested people for whom this is <em>not</em> obvious, and even comes as a revelation. So that&#8217;s why I&#8217;m saying it.</p> <p>Again and again over the past twenty years, I&#8217;ve seen people reinvent the notion of a &#8220;simpler alternative&#8221; to Shor&#8217;s algorithm: one that cuts out all the difficulty of building a fault-tolerant quantum computer. In every case, the trouble, typically left unstated, has been that these alternatives <em>also</em> cut out the exponential speedup that&#8217;s Shor&#8217;s algorithm&#8217;s raison d&#8217;être.</p> <p>Our second example today of a quantum computing motte-and-bailey is the claim, by Toronto-based quantum computing startup <a href="https://www.xanadu.ai/">Xanadu</a>, that <a href="https://arxiv.org/abs/1612.01199">Gaussian BosonSampling</a> can be used to solve all sorts of graph problems, like graph isomorphism, graph similarity, and densest subgraph. As the co-inventor of <a href="https://en.wikipedia.org/wiki/Boson_sampling">BosonSampling</a>, few things would warm my heart more than finding an actual application for that model (besides quantum supremacy experiments and, perhaps, certified random number generation). But I still regard this as an open problem&#8212;if by &#8220;application,&#8221; we mean outperforming what you could&#8217;ve done classically.</p> <p>In papers (see for example <a href="https://arxiv.org/abs/1810.10644">here</a>, <a href="https://arxiv.org/abs/1905.12646">here</a>, <a href="https://arxiv.org/abs/1803.10730">here</a>), members of the Xanadu team have given all sorts of ways to take a graph, and encode it into an instance of Gaussian BosonSampling, in such a way that the output distribution will then reveal features of the graph, like its isomorphism type or its dense subgraphs. The trouble is that so far, I’ve seen no indications that this will actually lead to quantum algorithms that outperform the best classical algorithms, for any graph problems of practical interest.</p> <p>In the case of Densest Subgraph, the Xanadu folks use the output of a Gaussian BosonSampler to seed (that is, provide an initial guess for) a classical local search algorithm. They say they observe better results this way than if they seed that classical local search algorithm with completely random initial conditions. But of course, the real question is: could we get equally good results by seeding with the output of some <em>classical</em> heuristic? Or by solving Densest Subgraph with a different approach entirely? Given how hard it’s turned out to be just to <em>verify</em> that the outputs of a BosonSampling device come from such a device at all, it would seem astonishing if the answer to these questions wasn’t “yes.”</p> <p>In the case of Graph Isomorphism, the situation is even clearer. There, the central claim made by the Xanadu folks is that given a graph G, they can use a Gaussian BosonSampling device to sample a probability distribution that encodes G’s isomorphism type. So, isn’t this “promising” for solving GI with a quantum computer? All you’d need to do now is invent some fast classical algorithm that could look at the samples coming from two graphs G and H, and tell you whether the probability distributions were the same.</p> <p>Except, not really. While the Xanadu paper never says so, if all you want is to sample a distribution that encodes a graph’s isomorphism type, that’s easy to do classically! (I even put this on the final exam for my undergraduate Quantum Information Science course a couple weeks ago.) Here’s how: given as input a graph G, just output G but with its vertices randomly permuted. Indeed, this will even provide a further property, better than anything the BosonSampling approach has been shown to provide (or than it probably does provide): namely, if G and H are <em>not</em> isomorphic, then the two probability distributions will not only be different but will have disjoint supports. Alas, this still leaves us with the problem of distinguishing which distribution a given sample came from, which is as hard as Graph Isomorphism itself. None of these approaches, classical or quantum, seem to lead to any algorithm that’s subexponential time, let alone competitive with the <a href="https://www.scottaaronson.com/blog/?p=2521">“Babai approach”</a> of thinking really hard about graphs.</p> <p>All of this stuff falls victim to what I regard as the Fundamental Error of Quantum Algorithms Research: namely, to treat it as &#8220;promising&#8221; that a quantum algorithm works at all, or works better than some brute-force classical algorithm, without asking yourself whether there are any indications that your approach will <em>ever</em> be able to exploit interference of amplitudes to outperform the <em>best</em> classical algorithm.</p> <p>Incidentally, I’m not sure exactly why, but in practice, a major red flag that the Fundamental Error is about to be committed is when someone starts talking about “hybrid quantum/classical algorithms.” By this they seem to mean: “outside the domain of traditional quantum algorithms, so don’t judge us by the standards of that domain.” But I liked the way someone at Q2B put it to me: <em>every</em> quantum algorithm is a “hybrid quantum/classical algorithm,” with classical processors used wherever they can be, and qubits used only where they must be.</p> <p>The other thing people do, when challenged, is to say “well, admittedly we have no <em>rigorous proof</em> of an asymptotic quantum speedup”—thereby brilliantly reframing the whole conversation, to make people like me look like churlish theoreticians insisting on impossible and perhaps irrelevant standard of rigor, blind to some huge practical quantum speedup that’s about to change the world. The real issue, of course, is not that they haven’t given a <em>proof</em> of a quantum speedup (in either the real world or the black-box world); rather, it’s that they’ve typically given no reasons whatsoever to think that there <em>might</em> be a quantum speedup, compared to the best classical algorithms out there.</p> <p>In the holiday spirit, let me end on a positive note. When I did the Q&amp;A at Q2B&#8212;the same one where Sarah Kaiser asked me to comment on &#8220;quantum supremacy&#8221;&#8212;one of my answers touched on the most important theoretical open problems about sampling-based quantum supremacy experiments. At the top of the list, I said, was whether there&#8217;s some interactive protocol by which a near-term quantum computer can not only exhibit quantum supremacy, but <em>prove</em> it to a polynomial-time-bounded classical skeptic. I mentioned that there was <em>one</em> proposal for how to do this, in the IQP model, due to <a href="https://arxiv.org/abs/0809.0847">Bremner and Shepherd</a>, from way back in 2008. I said that their proposal deserved much more attention than it had received, and that trying to break it would be one obvious thing to work on. Little did I know that, <strong>literally while I was speaking</strong>, a <a href="https://arxiv.org/abs/1912.05547">paper was being posted to the arXiv</a>, by Gregory Kahanamoku-Meyer, that claims to break Bremner and Shepherd&#8217;s scheme. I haven&#8217;t yet studied the paper, but assuming it&#8217;s correct, it represents the first clear progress on this problem in years (even though of a negative kind). Cool!!</p> Complexity Quantum Scott In leap for quantum computing, silicon quantum bits establish a long-distance relationship https://www.sciencedaily.com/releases/2019/12/191226084357.htm Quantum Computers News -- ScienceDaily urn:uuid:63db8dac-9ba5-1a65-2121-c405b6de6a68 Thu, 26 Dec 2019 13:43:57 +0000 In an important step forward in the quest to build a quantum computer using silicon-based hardware, researchers have succeeded in making possible the exchange of information between two qubits located relatively far apart -- about the length of a grain of rice, which is a considerable distance on a computer chip. Connecting two silicon qubits across this distance makes possible new and more complex silicon-based quantum computer circuits. NIPS vs. NeurIPS: guest post by Steven Pinker https://www.scottaaronson.com/blog/?p=4476 Shtetl-Optimized urn:uuid:b90f4712-0908-fd89-104a-bc3465109589 Mon, 23 Dec 2019 17:45:59 +0000 Scott&#8217;s prologue: Happy Christmas and Merry Chanukah! As a followup to last Thursday&#8217;s post about the term &#8220;quantum supremacy,&#8221; today all of us here at Shtetl-Optimized are humbled to host a guest post by Steven Pinker: the Johnstone Professor of Psychology at Harvard University, and author of The Language Instinct, How the Mind Works, The [&#8230;] <p><strong>Scott&#8217;s prologue:</strong></p> <p>Happy Christmas and Merry Chanukah!</p> <p>As a followup to <a href="https://www.scottaaronson.com/blog/?p=4450">last Thursday&#8217;s post</a> about the term &#8220;quantum supremacy,&#8221; today all of us here at <em>Shtetl-Optimized</em> are humbled to host a guest post by <a href="https://stevenpinker.com/">Steven Pinker</a>: the Johnstone Professor of Psychology at Harvard University, and author of <em><a href="https://www.amazon.com/Language-Instinct-How-Mind-Creates/dp/1491514981">The Language Instinct</a></em>, <em><a href="https://www.amazon.com/How-Mind-Works-Steven-Pinker/dp/0393318486">How the Mind Works</a></em>, <em><a href="https://www.amazon.com/Blank-Slate-Modern-Denial-Nature/dp/0142003344/ref=sr_1_1?keywords=the+blank+slate&amp;qid=1577123601&amp;s=books&amp;sr=1-1">The Blank Slate</a></em>, <em><a href="https://www.amazon.com/Enlightenment-Now-Science-Humanism-Progress/dp/0525427570">Enlightenment Now</a></em> (which I <a href="https://www.scottaaronson.com/blog/?p=3654">reviewed here</a>), and other books.</p> <p>The former NIPS—<a href="https://nips.cc/">Neural Information Processing Systems</a>—has been the premier conference for machine learning for 30 years. As many readers might know, last year NIPS <a href="https://www.nature.com/articles/d41586-018-07476-w">changed its name to NeurIPS</a>: ironically, giving greater emphasis to an aspect that I&#8217;m told has been <em>de</em>-emphasized at that conference over time. The reason, apparently, was that some male attendees had made puns involving the acronym &#8220;NIPS&#8221; and nipples.</p> <p>I confess that the name change took me by surprise, simply because it had never occurred to me to make the NIPS/nipples connection—not when I gave a <a href="https://www.scottaaronson.com/blog/?p=1246">plenary at NIPS</a> in 2012, and not when my collaborators and I coauthored a <a href="https://arxiv.org/abs/1802.09025">NIPS paper</a>. It’s not that I’m averse to puerile humor. It&#8217;s just that neither I, nor anyone else I knew, had apparently ever felt the need for a shorthand for &#8220;nipples.&#8221; Of course, once I <em>did</em> learn about this controversy, it became hard to hear &#8220;NIPS&#8221; without thinking about it.</p> <p>Back when this happened, Steven Pinker <a href="https://twitter.com/sapinker/status/1070364941494992896?lang=en">tweeted</a> about NIPS being &#8220;forced to change its acronym &#8230; because some thought it was sexist. ?????,&#8221; apparently as part of a longer <a href="https://twitter.com/sapinker/status/1070364369207341056?lang=en">thread</a> about &#8220;the new Victorians.&#8221; In response, a computer science professor sent Pinker an extremely stern email, saying that Pinker&#8217;s tweeting about this had &#8220;caused harm to our community&#8221; and &#8220;just [made] the world a bleaker place for everyone.&#8221; The email ended: &#8220;I hope you will choose to inform yourself on the discussion to which you have just contributed and that you will offer a well-considered follow up.&#8221; I won&#8217;t risk betraying confidences by quoting further. Of course, the author is warmly welcomed to share anything they wish in the comments here (or I can add it to the main post).</p> <p>Steve’s guest post today consists of his response to this correspondence. (He told me that, after sending it, he received no further responses.)</p> <p>I don’t have any dog in the NIPS/NeurIPS debate, being at most on the <a href="https://en.wikipedia.org/wiki/Margin_(machine_learning)">&#8220;margin&#8221;</a> (har har) of machine learning. And in any case the debate ended a year ago: the name is now NeurIPS and it’s not changing back. Reopening the issue would seem to invite a strong risk of social-media denunciation for no possible gain.</p> <p>So why am I doing this? Mostly because I thought it was in the interest of humanity to know that, even when Steven Pinker is answering someone’s email, with no expectation that his reply will be made public, he writes the same way he does in his books: with clarity, humor, and an amusing quote from his mom.</p> <p>But also because&#8212;again, without taking a position on the NIPS vs. NeurIPS issue itself&#8212;there&#8217;s a tactic displayed by Pinker&#8217;s detractors that fundamentally grates on me. This is where you pretend to an open mind, but it turns out that you&#8217;re open only to the possibility that your opponent might not have read enough reports and studies to &#8220;do better&#8221;&#8212;i.e., that they sinned out of ignorance rather than out of malice. You don&#8217;t open your mind even a crack to the possibility that the opponent might have a point.</p> <p><strong>Without further ado, here&#8217;s Steven Pinker&#8217;s email:</strong></p> <p>I appreciate your frank comments. At the same time, I do not agree with them. Please allow me to explain.</p> <p>If this were a matter of sexual harassment or other hostile behavior toward women, I would of course support strong measures to combat it. Any member of the Symposium who uttered demeaning comments toward or about women certainly deserves censure.</p> <p>But that is not what is at issue here. It’s an utterly irrelevant matter: the three-decades-old acronym for the Neural Information Processing Symposium, the pleasingly pronounceable NIPS. To state what should be obvious:&nbsp;<em>nip</em>&nbsp;is not a sexual word. As Chair of the Usage Panel of the&nbsp;<em>American Heritage Dictionary,&nbsp;</em>I can <a href="https://www.ahdictionary.com/word/search.html?q=nip">support this claim</a>.</p> <p>(And as my mother wrote to me: “I don’t get it. I thought Nips was a brand of caramel candy.”) &nbsp;[<a href="https://www.amazon.com/Nips-Coffee-Candy-4-Ounce-Boxes/dp/B000V9EIEE">Indeed</a>, I enjoyed those candies as a kid. &#8211;SA] Even if people with an adolescent mindset think of nipples when hearing the sound “nips,” the society should not endorse the idea that the concept of nipples is sexist. Men have nipples too, and women’s nipples evolved as organs of nursing, not sexual gratification. Indeed, many feminists have argued that it’s sexist to conceptualize women’s bodies from the point of view of male sexuality.</p> <p>If some people make insulting puns that demean women, the society should condemn them for the insults, not concede to their puerility by endorsing their appropriation of an innocent sound. (The Linguistics Society of America and Boston Debate League do not change their names to disavow jejune clichés about cunning linguists and master debaters.) To act as if anything with the remotest connection to sexuality must be censored to protect delicate female sensibilities is insulting to women and reminiscent of prissy Victorian taboos against uncovered piano legs or the phrase “with the naked eye.”</p> <p>Any harm to the community of computer scientists has been done not by me but by the pressure group and the Symposium’s surrender. As a public figure who hears from a broad range of people outside the academic bubble, I can tell you that this episode has not played well. It’s seen as the latest sign that academia has lost its mind—that it has traded reasoned argument, conceptual rigor, proportionality, and common sense for prudish censoriousness, snowflake sensibility, and virtue signaling. I often hear from intelligent non-leftists, “Why should I be impressed by the scientific consensus on climate change? Everyone knows that academics just fall into line with the politically correct position.” To secure the credibility of the academy, we have to make reasoned distinctions, and stop turning our enterprise into a laughingstock.</p> <p>To repeat: none of this deprecates the important effort to stamp out harassment and misogyny in science, which I’m well aware of and thoroughly support, but which has nothing to do with the acronym NIPS.</p> <p>You are welcome to share this note with interested parties.</p> <p>Best,<br>Steve</p> Nerd Interest Procrastination Scott The coolest LEGO ® in the universe https://www.sciencedaily.com/releases/2019/12/191223095357.htm Quantum Computers News -- ScienceDaily urn:uuid:59e45f89-74a0-b605-0abe-8ad9dafb759a Mon, 23 Dec 2019 14:53:57 +0000 For the first time, LEGO ® has been cooled to the lowest temperature possible in an experiment which reveals a new use for the popular toy -- the development of quantum computing. A figure and four blocks were placed inside the most effective refrigerator in the world, capable of reaching 1.6 millidegrees above absolute zero (minus 273.15 Centigrade), which is about 200,000 times colder than room temperature and 2,000 times colder than deep space. U.S. Government Soliciting Proposals for Quantum Characterization of Intermediate Scale Systems https://quantumcomputingreport.com/news/u-s-government-soliciting-proposals-for-quantum-characterization-of-intermediate-scale-systems/ Quantum Computing Report urn:uuid:517d6fb4-dc66-f20f-55f3-cc65a0a0c9eb Fri, 20 Dec 2019 21:12:17 +0000 In a Broad Agency Announcement (BAA) the U.S. Army Research Office (ARO) in association with the National Security Agency (NSA) are soliciting proposals to research efficient and practical protocols and techniques that allow Quantum Characterization, Verification, and Validation (QCVV) of larger systems with direct relevance to Fault Tolerant Quantum Computing (FTQC), and to demonstrate these [&#8230;] <p>In a Broad Agency Announcement (BAA) the U.S. Army Research Office (ARO) in association with the National Security Agency (NSA) are soliciting proposals to research efficient and practical protocols and techniques that allow Quantum Characterization, Verification, and Validation (QCVV) of larger systems with direct relevance to Fault Tolerant Quantum Computing (FTQC), and to demonstrate these protocols on intermediate-scale systems 10-20 qubits in size. Much of the previous work performed to characterize quantum qubits has been performed using one and two qubit measurements such as the qubit fidelity measurements that we show on our <a href="https://quantumcomputingreport.com/scorecards/qubit-quality/">Qubit Quality</a> page. However, as systems get larger with an eye towards building fault tolerant machines the number of measurements to fully characterize a system using these previous approaches would grow exponentially.&nbsp; It would be helpful to develop ways of evaluating these machines by selectively characterizing only the subset of information relevant to FTQC.&nbsp; The purpose of this program will be to research proposals and techniques to achieve this.</p> <p>The BAA is requesting proposals in two categories.&nbsp; The first is for integrating theoretical and experimental research to identify and address the challenges of QCVV for intermediate-scale quantum systems. The second is for theoretical research that may significantly advance QCVV through novel approaches.&nbsp; The agencies expect to make multiple awards with a maximum of $1.5M per year for each Category 1 awards, $700K per year for each Category 2 awards and $400K per year for each Category 2 awards that are theory only. The program and awards are expected to run for a four year period.</p> <p>The BAA is available for Institutions of higher education (foreign and domestic), nonprofit organizations, and for-profit concerns (large and small businesses). Those interested in applying are encouraged to submit white papers by January 28, 2020 with a final proposal due by March 17, 2020.</p> <p>For those interested in reading the full BAA, you can find a summary along with a link to download the full PDF file on the government’s contract opportunity site <a href="https://beta.sam.gov/opp/4e2a92e50c67472785de05973051463a/view?index=opp&amp;page=4">here</a>.</p> <p class="has-text-align-right has-small-font-size">December 20, 2019</p> dougfinke1 No tempest in a teacup -- it's a cyclone on a silicon chip https://www.sciencedaily.com/releases/2019/12/191220095434.htm Quantum Computers News -- ScienceDaily urn:uuid:c8c8aae0-1687-2631-f4c1-2df118637793 Fri, 20 Dec 2019 14:54:34 +0000 Researchers have combined quantum liquids and silicon-chip technology to study turbulence for the first time, opening the door to new navigation technologies and improved understanding of the turbulent dynamics of cyclones and other extreme weather. New research puts a spin on environmental defects https://uwaterloo.ca/institute-for-quantum-computing/news/new-research-puts-spin-environmental-defects Institute for Quantum Computing urn:uuid:dfea7a38-fd6a-c5f2-7c2f-843e5c7e7cb3 Fri, 20 Dec 2019 00:00:00 +0000 <img typeof="foaf:Image" src="https://uwaterloo.ca/institute-for-quantum-computing/sites/ca.institute-for-quantum-computing/files/styles/thumbnail/public/uploads/images/teaser.jpg?itok=HmC7oQIk" width="97" height="100" alt="Environmen-Assistanted Quantum-Enhanced Sensing with Repetitive Readout" /> <p>Friday, December 20, 2019</p> <p class="highlight">Magnetic fields are all around us—and even in us—all the time, and they often prove useful in technologies we rely on, like hard drives, MRI scanners and the power plants that provide us electricity.</p> <p>Measuring small magnetic fields at an atomic scale would allow even more applications in areas of physics, materials science, data storage and biomedical science, including characterizing the magnetic properties of thin-film materials, performing magnetic resonance imaging of single proteins and measuring neural activity at the level of single dendrites.</p> 12011 Japan-IBM Partnership Formed; IBM Q System One to Be Installed in Japan https://quantumcomputingreport.com/news/japan-ibm-partnership-formed-ibm-q-system-one-to-be-installed-in-japan/ Quantum Computing Report urn:uuid:852fa59e-82aa-451b-4aa6-030e250fd223 Thu, 19 Dec 2019 20:14:39 +0000 IBM and the University of Tokyo have announced a partnership to encourage and promote quantum computing research in Japan. This partnership is similar to one they established with Fraunhofer-Gesellschaft in Germany last September. Key elements of the program include: IBM will install an IBM Q System One at an IBM facility in Japan. This will [&#8230;] <p>IBM and the University of Tokyo have announced a partnership to encourage and promote quantum computing research in Japan. This partnership is similar to one <a href="https://quantumcomputingreport.com/news/ibm-and-fraunhofer-partner-on-quantum-computing-initiative-for-germany/">they established with Fraunhofer-Gesellschaft in Germany last September</a>. Key elements of the program include:</p> <ul><li>IBM will install an IBM Q System One at an IBM facility in Japan. This will be IBM&#8217;s first quantum computer installation in Asia and only the second outside of the United States. It will provide students and researchers in Japan with the hands-on opportunity to explore quantum algorithms, applications and software and develop practical applications of quantum computing. </li><li>IBM and the University of Tokyo will set up a quantum system technology center for development of components and technologies, such as advanced cryogenic and microwave test capabilities, for next generation quantum computers.</li><li>IBM&#8217;s Japan quantum hub which they <a href="https://newsroom.ibm.com/2018-05-17-IBM-and-Keio-University-Announce-Collaborations-with-JSR-MUFG-Bank-Mizuho-Financial-Group-and-Mitsubishi-Chemical-to-Accelerate-Quantum-Computing-in-Japan">previously established with Keio University</a> will be expanded to encourage more companies to join and explore the benefits of quantum computing in a variety of industries including finance, chemistry and materials, pharma, automotive manufacturing and logistics. </li></ul> <p class="has-text-align-right has-small-font-size">December 19, 2019</p> dougfinke1 Scientists discover first antiferromagnetic topological quantum material https://www.sciencedaily.com/releases/2019/12/191219111433.htm Quantum Computers News -- ScienceDaily urn:uuid:2e8bb579-dccc-0161-1a87-046fd09c1c33 Thu, 19 Dec 2019 16:14:33 +0000 Scientists have discovered a new type of bulk quantum material with intrinsically magnetic and topological properties. The new material is called manganese-bismuth telluride (MnBi2Te4) and is extremely promising for application in antiferromagnetic spintronics and quantum technologies. Quantum Dominance, Hegemony, and Superiority https://www.scottaaronson.com/blog/?p=4450 Shtetl-Optimized urn:uuid:d176e851-704b-cbb3-d671-3d2976b61d48 Thu, 19 Dec 2019 09:17:02 +0000 Yay! I&#8217;m now a Fellow of the ACM. Along with my fellow new inductee Peter Shor, who I hear is a real up-and-comer in the quantum computing field. I will seek to use this awesome responsibility to steer the ACM along the path of good rather than evil. Also, last week, I attended the Q2B [&#8230;] <p>Yay! I&#8217;m <a href="https://www.cs.utexas.edu/news/2019/professor-scott-aaronson-named-acm-fellow">now</a> a Fellow of the ACM. Along with my <a href="https://www.acm.org/media-center/2019/december/fellows-2019">fellow new inductee</a> Peter Shor, who I hear is a real up-and-comer in the quantum computing field. I will seek to use this awesome responsibility to steer the ACM along the path of good rather than evil.</p> <p>Also, last week, I attended the <a href="https://q2b.qcware.com/">Q2B</a> conference in San Jose, where a central theme was the outlook for practical quantum computing in the wake of the first clear demonstration of quantum computational supremacy. Thanks to the folks at <a href="https://qcware.com/">QC Ware</a> for organizing a fun conference (full disclosure: I&#8217;m QC Ware&#8217;s Chief Scientific Advisor). I&#8217;ll have more to say about the actual scientific things discussed at Q2B in future posts.</p> <p>None of that is why you&#8217;re here, though. You&#8217;re here because of the battle over &#8220;quantum supremacy.&#8221;</p> <p>A week ago, my good friend and <a href="https://www.smbc-comics.com/comic/the-talk-3">collaborator</a> Zach Weinersmith, of <a href="http://smbc-comics.com/">SMBC Comics</a>, put out a <a href="http://www.smbc-comics.com/comic/classical">cartoon</a> with a dark-curly-haired scientist named &#8220;Dr. Aaronson,&#8221; who&#8217;s revealed on a hot mic to be an evil &#8220;quantum supremacist.&#8221; Apparently a rush job, this cartoon is far from Zach&#8217;s finest work. For one thing, if the character is supposed to be me, why not draw him as me, and if he isn&#8217;t, why call him &#8220;Dr. Aaronson&#8221;? In any case, I learned from talking to Zach that the cartoon&#8217;s timing was purely coincidental: Zach didn&#8217;t even <em>realize</em> what a hornet&#8217;s-nest he was poking with this.</p> <p>Ever since John Preskill <a href="https://arxiv.org/abs/1203.5813">coined</a> it in 2012, &#8220;quantum supremacy&#8221; has been an awkward term. Much as I admire John Preskill&#8217;s wisdom, brilliance, generosity, and good sense, in physics as in everything else&#8212;yeah, &#8220;quantum supremacy&#8221; is not a term I would&#8217;ve coined, and it&#8217;s certainly not a hill I&#8217;d choose to die on. Once it had gained common currency, though, I sort of took a liking to it, mostly because I realized that I could mine it for dark one-liners in my talks.</p> <p>The thinking was: even as white supremacy was making its horrific resurgence in the US and around the world, here we were, physicists and computer scientists and mathematicians of varied skin tones and accents and genders, coming together to pursue a different and better kind of supremacy&#8212;a small reflection of the better world that we still believed was possible. You might say that we were <strong>reclaiming</strong> the word &#8220;supremacy&#8221;&#8212;which, after all, just means a state of being supreme&#8212;for something non-sexist and non-racist and inclusive and good.</p> <p>In the world of 2019, alas, perhaps it was inevitable that people wouldn&#8217;t leave things there.</p> <p>My first intimation came a month ago, when <a href="https://twitter.com/LeonieMueck?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor">Leonie Mueck</a>&#8212;someone who I&#8217;d gotten to know and like when she was an editor at <em>Nature</em> handling quantum information papers&#8212;emailed me about her view that our community should abandon the term &#8220;quantum supremacy,&#8221; because of its dark overtones, and potential to make women and minorities uncomfortable in our field. She advocated using &#8220;quantum advantage&#8221; instead.</p> <p>So I sent Leonie back a friendly reply, explaining that, as the father of a math-loving 6-year-old girl, I understood and shared her concerns&#8212;but also, that I also didn&#8217;t know an alternative term that really worked.</p> <p>See, it&#8217;s like this. Preskill meant &#8220;quantum supremacy&#8221; to refer to a <em>momentous event</em> that seemed likely to arrive in a matter of years: namely, the moment when programmable quantum computers would first outpace the ability of the fastest classical supercomputers on earth, running the fastest algorithms known by humans, to simulate what the quantum computers were doing (at least on special, contrived problems). And &#8230; &#8220;the historic milestone of quantum advantage&#8221;? It just doesn&#8217;t sound right. Plus, as many others pointed out, the term &#8220;quantum advantage&#8221; is already used to refer to &#8230; well, quantum <em>advantages</em>, which might fall well short of supremacy.</p> <p>But one could go further. Suppose we did switch to &#8220;quantum advantage.&#8221; Couldn&#8217;t that term, too, remind vulnerable people about the unfair advantages that some groups have over others? Indeed, while &#8220;advantage&#8221; is certainly subtler than &#8220;supremacy,&#8221; couldn&#8217;t that make it all the more insidious, and therefore dangerous?</p> <p>Oblivious though I sometimes am, I realized Leonie would be unhappy if I offered that, because of my wholehearted agreement, I would henceforth never again call it &#8220;quantum supremacy,&#8221; but only &#8220;quantum superiority,&#8221; &#8220;quantum dominance,&#8221; or &#8220;quantum hegemony.&#8221;</p> <p>But maybe you now see the problem. What word does the English language provide to describe one thing <em>decisively beating or</em> <em>being better than</em> a different thing for some purpose, and which <em>doesn&#8217;t</em> have any unsavory connotations?</p> <p>I&#8217;ve heard &#8220;quantum ascendancy,&#8221; but that makes it sound like we&#8217;re a UFO cult&#8212;waiting to ascend, like ytterbium ions caught in a laser beam, to a vast quantum computer in the sky.</p> <p>Or &#8220;quantum inimitability&#8221; (that is, inability to imitate using a classical computer), but who can pronounce that?</p> <p>Today, my brilliant former student <a href="https://ewintang.com/">Ewin Tang</a> (yes, <a href="https://www.scottaaronson.com/blog/?p=3880">that one</a>) relayed to me a suggestion by Kevin Tian: &#8220;quantum eclipse&#8221; (that is, the moment when quantum computers first eclipse classical ones for some task). But would one want to speak of a &#8220;quantum eclipse experiment&#8221;? And shouldn&#8217;t we expect that, the cuter and cleverer the term, the harder it will be to use unironically?</p> <p>In summary, while someone <em>might</em> think of a term so inspired that it immediately supplants &#8220;quantum supremacy&#8221; (and while I welcome suggestions), I currently regard it as an open problem.</p> <p>Anyway, evidently dissatisfied with my response, last week Leonie teamed up with 13 others to publish a <a href="https://www.nature.com/articles/d41586-019-03781-0">letter in <em>Nature</em></a>, which was originally entitled &#8220;Supremacy is for racists&#8212;use &#8216;quantum advantage,'&#8221; but whose title I see has now been changed to the milder &#8220;Instead of &#8216;supremacy&#8217; use &#8216;quantum advantage.'&#8221; Leonie&#8217;s co-signatories included four of my good friends and colleagues: Alan Aspuru-Guzik, Helmut Katzgraber, Anne Broadbent, and Chris Granade (the last of whom got started in the field by helping me edit <a href="https://www.amazon.com/Quantum-Computing-since-Democritus-Aaronson/dp/0521199565"><em>Quantum Computing Since Democritus</em></a>).</p> <p>Their letter says:</p> <blockquote class="wp-block-quote"><p>The community claims that quantum supremacy is a technical term with a specified meaning. However, any technical justification for this descriptor could get swamped as it enters the public arena after the intense media coverage of the past few months.</p><p>In our view, ‘supremacy’ has overtones of violence, neocolonialism and racism through its association with ‘white supremacy’. Inherently violent language has crept into other branches of science as well — in human and robotic spaceflight, for example, terms such as ‘conquest’, ‘colonization’ and ‘settlement’ evoke the <em>terra nullius</em> arguments of settler colonialism and must be contextualized against ongoing issues of neocolonialism.</p><p>Instead, quantum computing should be an open arena and an inspiration for a new generation of scientists.</p></blockquote> <p>When I did an &#8220;Ask Me Anything&#8221; session, as the closing event at Q2B, <a href="https://www.sckaiser.com/">Sarah Kaiser</a> asked me to comment on the <em>Nature</em> petition. So I repeated what I&#8217;d said in my emailed response to Leonie&#8212;running through the problems with each proposed alternative term, talking about the value of reclaiming the word &#8220;supremacy,&#8221; and mostly just trying to diffuse the tension by getting everyone laughing together. Sarah later <a href="https://twitter.com/crazy4pi314/status/1205288610297069568">tweeted</a> that she was &#8220;really disappointed&#8221; in my response.</p> <p>Then the <em>Wall Street Journal</em> got in on the action, with a brief <a href="https://www.wsj.com/articles/achieving-quantum-wokeness-11576540808">editorial</a> (warning: paywalled) mocking the <em>Nature</em> petition:</p> <blockquote class="wp-block-quote"><p>There it is, folks: Mankind has hit quantum wokeness. Our species, akin to Schrödinger’s cat, is simultaneously brilliant and brain-dead. We built a quantum computer and then argued about whether the write-up was linguistically racist.</p><p>Taken seriously, the renaming game will never end. First put a Sharpie to the Supremacy Clause of the U.S. Constitution, which says federal laws trump state laws. Cancel Matt Damon for his 2004 role in “The Bourne Supremacy.” Make the Air Force give up the term “air supremacy.” Tell lovers of supreme pizza to quit being so chauvinistic about their toppings. Please inform Motown legend Diana Ross that the Supremes are problematic.</p><p>The quirks of quantum mechanics, some people argue, are explained by the existence of many universes. How did we get stuck in this one? </p></blockquote> <p>Steven Pinker also weighed in, with a linguistically-informed <a href="https://twitter.com/sapinker/status/1206662965614825472">tweetstorm</a>:</p> <blockquote class="wp-block-quote"><p>This sounds like something from The Onion but actually appeared in Nature … It follows the wokified stigmatization of other innocent words, like &#8220;House Master&#8221; (now, at Harvard, Residential Dean) and &#8220;NIPS&#8221; (Neural Information Processing Society, now NeurIPS). It&#8217;s a familiar linguistic phenomenon, a lexical version of Gresham&#8217;s Law: bad meanings drive good ones out of circulation. Examples: the doomed &#8220;niggardly&#8221; (no relation to the n-word) and the original senses of &#8220;cock,&#8221; &#8220;ass,&#8221; &#8220;prick,&#8221; &#8220;pussy,&#8221; and &#8220;booty.&#8221; Still, the prissy banning of words by academics should be resisted. It dumbs down understanding of language: word meanings are conventions, not spells with magical powers, and all words have multiple senses, which are distinguished in context. Also, it makes academia a laughingstock, tars the innocent, and does nothing to combat actual racism &amp; sexism.</p></blockquote> <p>Others had a stronger reaction. <a href="https://en.wikipedia.org/wiki/Curtis_Yarvin">Curtis Yarvin</a>, better known as Mencius Moldbug, is one of the founders of &#8220;neoreaction&#8221; (and a significant influence on <a href="https://en.wikipedia.org/wiki/Steve_Bannon">Steve Bannon</a>, <a href="https://en.wikipedia.org/wiki/Michael_Anton">Michael Anton</a>, and other Trumpists). Regulars might remember that Yarvin argued with me in <em>Shtetl-Optimized</em>&#8216;s comment section, under a <a href="https://www.scottaaronson.com/blog/?p=3167">post</a> in which I denounced Trump&#8217;s travel ban and its effects on my Iranian PhD student. Since then, Yarvin has sent me many emails, which have ranged from long to <em>extremely</em> long, and whose message could be summarized as: &#8220;[labored breathing] Abandon your liberal Enlightenment pretensions, young Nerdwalker. Come over the Dark Side.&#8221;</p> <p>After the &#8220;supremacy is for racists&#8221; letter came out in <em>Nature</em>, though, Yarvin sent me his shortest email ever. It was simply a link to the letter, along with the comment &#8220;I knew it would come to this.&#8221;</p> <p>He meant: &#8220;What more proof do you need, young Nerdawan, that this performative wokeness is a cancer that will eventually infect everything you value&#8212;even totally apolitical research in quantum information? And by extension, that my whole worldview, which warned of this, is fundamentally correct, while your faith in liberal academia is naïve, and will be repaid only with backstabbing?&#8221;</p> <p>In a subsequent email, Yarvin predicted that in two years, the whole community will be saying &#8220;quantum advantage&#8221; instead of &#8220;quantum supremacy,&#8221; and in five years I&#8217;ll be saying &#8220;quantum advantage&#8221; too. As Yarvin <a href="https://www.unqualified-reservations.org/2009/01/gentle-introduction-to-unqualified/">famously wrote</a>: &#8220;Cthulhu may swim slowly. But he only swims left.&#8221;</p> <p>So what do I <em>really</em> think about this epic battle for (and against) supremacy?</p> <p>Truthfully, half of me just wants to switch to &#8220;quantum advantage&#8221; right now and be done with it. As I said, I know some of the signatories of the <em>Nature</em> letter to be smart and reasonable and kind. They don&#8217;t wish to rid the planet of everyone like me. They&#8217;re not Amanda Marcottes or Arthur Chus. Furthermore, there&#8217;s little I despise more than a meaty scientific debate devolving into a pointless semantic one, with brilliant friend after brilliant friend getting sucked into the vortex (&#8220;you too?&#8221;). I&#8217;m strongly in the Pinkerian camp, which holds that words are just arbitrary designators, devoid of the totemic power to dictate thoughts. So if friends and colleagues&#8212;even just a few of them&#8212;tell me that they find some word I use to be offensive, why not just be a <em>mensch</em>, apologize for any unintended hurt, switch words midsentence, and continue discussing the matter at hand?</p> <p>But then the other half of me wonders: once we&#8217;ve ceded an open-ended veto over technical terms that remind anyone of anything bad, <em>where does it stop?</em> How do we ever certify a term as kosher? At what point do we all get to stop arguing and laugh together? </p> <p>To make things concrete, look back at <a href="https://twitter.com/crazy4pi314/status/1205288610297069568">Sarah Kaiser&#8217;s Twitter thread</a>&#8212;the one where she expresses disappointment in me. Below her tweet, someone remarks that, besides &#8220;quantum supremacy,&#8221; the word &#8220;ancilla&#8221; (as in <a href="https://en.wikipedia.org/wiki/Ancilla_bit">ancilla qubit</a>, a qubit used for intermediate computation or other auxiliary purposes) is problematic as well. Here&#8217;s Sarah&#8217;s response:</p> <blockquote class="wp-block-quote"><p>I agree, but I wanted to start by focusing on the obvious one, Its harder for them to object to just one to start with, then once they admit the logic, we can expand the list</p></blockquote> <p>(What would Curtis Yarvin say about that?)</p> <p>You&#8217;re probably now wondering: what&#8217;s wrong with &#8220;ancilla&#8221;? <a href="https://arxiv.org/abs/1705.06768">Apparently</a>, in ancient Rome, an <a href="https://en.wiktionary.org/wiki/ancilla">&#8220;ancilla&#8221;</a> was a female slave, and indeed that&#8217;s the Latin root of the English adjective <a href="https://www.merriam-webster.com/dictionary/ancillary">&#8220;ancillary&#8221;</a> (as in &#8220;providing support to&#8221;). I confess that I hadn&#8217;t known that&#8212;had you? Admittedly, once you <em>do</em> know, you might never again look at a <a href="https://en.wikipedia.org/wiki/Controlled_NOT_gate">Controlled-NOT gate</a>&#8212;pitilessly flipping an ancilla qubit, subject only to the whims of a nearby control qubit&#8212;in quite the same way.</p> <p>(Ah, but the ancilla can fight back against her controller! And she does&#8212;in the Hadamard basis.)</p> <p>The thing is, if we&#8217;re gonna play this game: what about <a href="https://en.wikipedia.org/wiki/Creation_and_annihilation_operators">annihilation operators</a>? Won&#8217;t those need to be &#8230; annihilated from physics?</p> <p>And what about <a href="https://en.wikipedia.org/wiki/Unitary_matrix">unitary matrices</a>? Doesn&#8217;t their very name negate the multiplicity of perspectives and cultures?</p> <p>What about Dirac&#8217;s oddly-named <a href="https://en.wikipedia.org/wiki/Bra%E2%80%93ket_notation">bra/ket notation</a>, with its limitless potential for puerile jokes, about the &#8220;bra&#8221; vectors displaying their contents horizontally and so forth? (Did you smile at that, you hateful pig?)</p> <p>What about <a href="https://en.wikipedia.org/wiki/Hermitian_adjoint">daggers</a>? Don&#8217;t we need a less violent conjugate tranpose?</p> <p>Not to beat a dead horse, but once you hunt for examples, you realize that the whole dictionary is shot through with domination and brutality&#8212;that you&#8217;d have to massacre the English language to take it out. There&#8217;s nothing special about math or physics in this respect.</p> <p>The same half of me also thinks about my friends and colleagues who oppose claims of quantum supremacy, or even the quest for quantum supremacy, on various <em>scientific</em> grounds. I.e., either they don&#8217;t think that the Google team achieved what it said, or they think that the task wasn&#8217;t hard enough for classical computers, or they think that the entire goal is misguided or irrelevant or uninteresting.</p> <p>Which is fine&#8212;these are precisely the arguments we <em>should </em>be having&#8212;except that I&#8217;ve personally seen some of my respected colleagues, while arguing for these positions, opportunistically tack on ideological objections to the term &#8220;quantum supremacy.&#8221; Just to goose up their case, I guess. And I confess that every time they did this, it made me want to keep saying &#8220;quantum supremacy&#8221; from now till the end of time&#8212;<em>solely to deny these colleagues a cheap and unearned &#8220;victory,&#8221; one they apparently felt they couldn&#8217;t obtain on the merits alone.</em> I realize that this is childish and irrational.</p> <p>Most of all, though, the half of me that I&#8217;m talking about thinks about Curtis Yarvin and the <em>Wall Street Journal</em> editorial board, cackling with glee to see their worldview so dramatically confirmed&#8212;as theatrical wokeness, that self-parodying modern monstrosity, turns its gaze on (of all things) quantum computing research. More red meat to fire up the base&#8212;or at least that sliver of the base nerdy enough to care. And the left, as usual, walks right into the trap, sacrificing its credibility with the outside world to pursue a runaway virtue-signaling spiral.</p> <p>The same half of me thinks: do we <em>really</em> want to fight racism and sexism? Then let&#8217;s work together to assemble a broad coalition that can defeat Trump. And Jair Bolsonaro, and Viktor Orbán, and all the other ghastly manifestations of humanity&#8217;s collective lizard-brain. Then, if we&#8217;re really fantasizing, we could liberalize the drug laws, and get contraception and loans and education to women in the Third World, and stop the systematic disenfranchisement of black voters, and open up the world&#8217;s richer, whiter, and higher-elevation countries to climate refugees, and protect the world&#8217;s remaining indigenous lands (those that didn&#8217;t burn to the ground this year).</p> <p>In this context, the trouble with obsessing over terms like &#8220;quantum supremacy&#8221; is not merely that it diverts attention, while contributing nothing to fighting the world&#8217;s actual racism and sexism. The trouble is that the obsessions are actually <em>harmful</em>. For they make academics&#8212;along with progressive activists&#8212;look silly. They make people think that we must not have meant it when we talked about the existential urgency of climate change and the world&#8217;s other crises. They pump oxygen into right-wing echo chambers.</p> <p>But it&#8217;s worse than ridiculous, because of the message that I fear is received by many outside the activists&#8217; bubble. When you <em>say</em> stuff like &#8220;[quantum] supremacy is for racists,&#8221; what&#8217;s <em>heard</em> might be something more like:</p> <blockquote class="wp-block-quote"><p>&#8220;Watch your back, you disgusting supremacist. Yes, <em>you</em>. You claim that you mentor women and minorities, donate to good causes, try hard to confront the demons in your own character? Ha! None of that counts for anything with us. You&#8217;ll never be with-it enough to be our ally, so don&#8217;t bother trying. We&#8217;ll see to it that you&#8217;re never safe, not even in the most abstruse and apolitical fields. We&#8217;ll comb through your words&#8212;even words like &#8216;ancilla qubit&#8217;&#8212;-looking for any that we can cast as offensive by our opaque and ever-shifting standards. And once we find Obviously I'm Not Defending Aaronson Quantum The Fate of Humanity Scott Topological materials for information technology offer lossless transmission of signals https://www.sciencedaily.com/releases/2019/12/191218153537.htm Quantum Computers News -- ScienceDaily urn:uuid:dcc063ec-f9f4-5179-2ed2-cc2f230764e8 Wed, 18 Dec 2019 20:35:37 +0000 New experiments with magnetically doped topological insulators at BESSY II have revealed possible ways of lossless signal transmission that involve a surprising self-organizational phenomenon. In the future, it might be possible to develop materials that display this phenomenon at room temperature and can be used as processing units in a quantum computer, for example. Scientists correlate photon pairs of different colors generated in separate buildings https://www.sciencedaily.com/releases/2019/12/191217152927.htm Quantum Computers News -- ScienceDaily urn:uuid:3f7b679c-f829-6623-ef8d-c6af663a133c Tue, 17 Dec 2019 20:29:27 +0000 The interference between two photons could connect distant quantum processors, enabling an internet-like quantum computer network. Observations from the 2019 Q2B Conference https://quantumcomputingreport.com/our-take/observations-from-the-2019-q2b-conference/ Quantum Computing Report urn:uuid:c3507667-a9fa-6c08-342d-4342ee503396 Sun, 15 Dec 2019 00:48:14 +0000 I recently attended the third annual Q2B Conference on December 10-12, 2019 in San Jose, California.  The Q2B conference continues to grow and had about 540 attendees representing many different quantum hardware/software companies, end users, universities, government agencies, and venture capital communities. This number is double the attendance of the first Q2B conference in 2017. [&#8230;] <p>I recently attended the third annual Q2B Conference on December 10-12, 2019 in San Jose, California.  The Q2B conference continues to grow and had about 540 attendees representing many different quantum hardware/software companies, end users, universities, government agencies, and venture capital communities. This number is double the attendance of the first Q2B conference in 2017.</p> <p>This report is not a comprehensive listing of everything that went on at the conference.&nbsp; There were several sessions that occurred in parallel and I needed to choose which ones to attend.&nbsp; In addition, there were several sessions that covered topics that were similar to items covered in other conferences, published technical papers or previous Q2B events.&nbsp; So I will only cover those items that I found new, interesting and relevant.&nbsp; My apologies in advance to those folks who wanted to know about things that I do not cover here.&nbsp; However, QC Ware did record videos of all the presentations and will be posting most of the videos and presentations from the conference within the next month or two.</p> <p><strong>Google</strong><br>John Martinis presented the Sycamore chip and the previously published results of the Quantum Supremacy experiment.&nbsp; But the most interesting part of his talk was when he mentioned that they have already fabricated an improved version of the Sycamore chip and were currently testing it. Although he didn’t disclose full details of the chip, he did hint that the number of qubits have been increased from 53 to 57+.&nbsp; Also, this new device should have even better performance than Sycamore with a particular mention of improved readout fidelity.</p> <p><strong>IBM</strong><br>Anthony Annunziata discussed the IBM Q systems and the IBM Q Network. They current have a total of 15 systems available in the cloud. The most interesting thing for us in this presentation was the announcement that they were opening up access to the OpenPulse API for people who want to research how to control the pulses that perform the actual control of the qubits. This will require newly released version 0.14 of Qiskit but will allow people to control the pulses over the cloud for the first time.&nbsp; More about this can be found in a newly released IBM quantum computing blog entry titled <a href="https://www.ibm.com/blogs/research/2019/12/qiskit-openpulse/">Get to the heart of real quantum hardware</a>.</p> <p><strong>Microsoft</strong><br>The most significant thing to us at Q2B was not the presentation itself, but the display in a glass case at their booth of a new cryo-CMOS control chip.&nbsp; The chip would be able to potentially control up to 50,000 qubits with just three wires that come in from outside the fridge. We recently posted a news article describing this chip in more detail and you can find the article <a href="https://quantumcomputingreport.com/news/intel-microsoft-disclose-cryo-cmos-quantum-control-chips/">here</a>. </p> <p><strong>Honeywell</strong><br>Honeywell has been in stealth mode with their ion trap technology development, but they pulled the curtains open slightly with a presentation by Tony Uttley. Although he didn’t mention too many of the technical details of their machines, he did mention three advantages that they have including long coherence time qubits, high resolutions for qubit rotations, and the ability to take a measurement on a single qubit and do conditional executions based upon the result  (a quantum IF statement, if you will). This capability is enabled by the long coherence times of the ion traps and their ability to take the measurement on one qubit while keeping all the others in their quantum state. Although we will need to see the details of this when Honeywell has the broad commercial launch of their machines in the Spring of 2020 to fully understand how it works, we are not aware of any of the other quantum platforms currently having this capability. Later on, in a software session, one of their researchers Mike Foss-Feig presented a paper titled “Solving large problems with small quantum computers” that appears to utilize this capability.</p> <p><strong>Rigetti</strong><br>Chad Rigetti discussed their 32-qubit Aspen-7 processor and their newly announced relationship with Amazon Web Services.  We had previously covered this in a news article published earlier this month which you can see <a href="https://quantumcomputingreport.com/news/#RIGETTI32QUBIT">here</a>. However, in his presentation he disclosed for the first time that they had implemented a new and additional family of parameterized two-qubit gates in their architecture called the XY(θ) gate.  And when the value of θ is equal to dougfinke1 D-Wave Announces New CEO and Signs Agreements with NEC https://quantumcomputingreport.com/news/d-wave-announces-new-ceo-and-signs-agreements-with-nec/ Quantum Computing Report urn:uuid:06078a3b-9f52-098b-daf1-cd257d5d16ec Sat, 14 Dec 2019 19:49:25 +0000 D-Wave is finishing the year with a pair of announcements. First, it indicated that CEO Vern Brownell will be retiring at the end of the year and that current chief product officer and executive vice president of research and development Alan Baratz will take over as CEO. Baratz joined D-Wave in 2017 and has overseen [&#8230;] <p>D-Wave is finishing the year with a pair of announcements. First, it indicated that CEO Vern Brownell will be retiring at the end of the year and that current chief product officer and executive vice president of research and development Alan Baratz will take over as CEO. Baratz joined D-Wave in 2017 and has overseen many of the recent developments including launch of the <a href="https://www.dwavesys.com/take-leap">Leap<img src="https://s.w.org/images/core/emoji/12.0.0-1/72x72/2122.png" alt="™" class="wp-smiley" style="height: 1em; max-height: 1em;" /> Cloud Service</a> as well as the development of D-Wave&#8217;s next-generation <a href="https://www.globenewswire.com/news-release/2019/09/24/1920261/0/en/What-s-in-a-Name-D-Wave-Unveils-Next-Generation-System-Name-Announces-First-Next-Generation-System-Customer-Demonstrates-Lower-Noise-Performance.html">Advantage<img src="https://s.w.org/images/core/emoji/12.0.0-1/72x72/2122.png" alt="™" class="wp-smiley" style="height: 1em; max-height: 1em;" /> quantum system</a>. At this time, we are not expecting any significant changes in D-Wave&#8217;s strategy due to this management change.</p> <p>The agreements with NEC will include several areas of activity. NEC will be able to act as an authorized reseller of D-Wave&#8217;s Leap cloud service, they will jointly work with D-Wave to provide applications support and development for customers in Japan, and finally, the two companies will jointly develop hybrid services that combine the power of NEC’s supercomputers and other classical systems with D-Wave’s quantum technology including <a href="https://docs.ocean.dwavesys.com/projects/hybrid/en/latest/">D-Wave Hybrid<img src="https://s.w.org/images/core/emoji/12.0.0-1/72x72/2122.png" alt="™" class="wp-smiley" style="height: 1em; max-height: 1em;" /></a>, an open-source workflow platform for building and running quantum-classical hybrid applications. NEC will also be making a financial investment of $10 million into D-Wave and this is expected to close shortly.</p> <p>For more, you can view the news release about the CEO change on the D-Wave web site <a href="https://www.dwavesys.com/press-releases/d-wave-announces-promotion-dr-alan-baratz-ceo">here</a> and the news release about the agreements with NEC <a href="https://www.dwavesys.com/press-releases/d-wave-signs-agreements-nec-accelerate-commercial-quantum-computing">here</a>.</p> dougfinke1 Building a better clock https://uwaterloo.ca/institute-for-quantum-computing/news/building-better-clock Institute for Quantum Computing urn:uuid:1841aaaa-c7e8-776f-5bee-2cd53b934987 Thu, 12 Dec 2019 00:00:00 +0000 <img typeof="foaf:Image" src="https://uwaterloo.ca/institute-for-quantum-computing/sites/ca.institute-for-quantum-computing/files/styles/thumbnail/public/uploads/images/mypicture_0.jpg?itok=dXPDifZY" width="67" height="100" alt="IQC researcher Alexandre Cooper-Roy" /> <p>Thursday, December 12, 2019</p> <p>The best clocks in the world can keep time so accurately that they only lose one second in millions or even billions of years. Yet, researchers are still fervently pursuing ever better clocks. Once a certain threshold of clock accuracy and stability is crossed, it will open up tremendous opportunities to understand the universe and to develop quantum technologies like accelerometers, gravimeters, and communication systems.</p> 12011 Heat energy leaps through empty space, thanks to quantum weirdness https://www.sciencedaily.com/releases/2019/12/191211145600.htm Quantum Computers News -- ScienceDaily urn:uuid:dfd4cb92-df7d-1891-694b-b44a537c1a8c Wed, 11 Dec 2019 19:56:00 +0000 A surprising new study shows that heat energy can leap across a few hundred nanometers of a complete vacuum, thanks to a quantum mechanical phenomenon called the Casimir interaction. Though this interaction is only significant on very short length scales, it could have profound implications for the design of computer chips and other nanoscale electronic components where heat dissipation is key, while upending what many of us learned about heat transfer in high school physics. New laser technique images quantum world in a trillionth of a second https://www.sciencedaily.com/releases/2019/12/191210111649.htm Quantum Computers News -- ScienceDaily urn:uuid:c66b8971-b069-03fb-a955-d680cc58388e Tue, 10 Dec 2019 16:16:49 +0000 For the first time, researchers have been able to record, frame-by-frame, how an electron interacts with certain atomic vibrations in a solid. The technique captures a process that commonly causes electrical resistance in materials while, in others, can cause the absence of resistance, or superconductivity. Gamma-ray laser moves a step closer to reality https://www.sciencedaily.com/releases/2019/12/191206152937.htm Quantum Computers News -- ScienceDaily urn:uuid:dd570af3-cae2-a67a-8749-12c92baac88e Fri, 06 Dec 2019 20:29:37 +0000 A physicist has performed calculations showing hollow spherical bubbles filled with a gas of positronium atoms are stable in liquid helium. The calculations take scientists a step closer to realizing a gamma-ray laser. A platform for stable quantum computing, a playground for exotic physics https://www.sciencedaily.com/releases/2019/12/191205130536.htm Quantum Computers News -- ScienceDaily urn:uuid:7680591b-2636-12d9-cc8f-6aa7f7995ef6 Thu, 05 Dec 2019 18:05:36 +0000 Researchers have demonstrated the first material that can have both strongly correlated electron interactions and topological properties, which not only paves the way for more stable quantum computing but also an entirely new platform to explore the wild world of exotic physics. A new carbon nanotube-based filter for quantum computing applications https://uwaterloo.ca/institute-for-quantum-computing/news/new-carbon-nanotube-based-filter-quantum-computing Institute for Quantum Computing urn:uuid:627945b3-945f-dd43-127b-9f1714c93dca Wed, 04 Dec 2019 00:00:00 +0000 <img typeof="foaf:Image" src="https://uwaterloo.ca/institute-for-quantum-computing/sites/ca.institute-for-quantum-computing/files/styles/thumbnail/public/uploads/images/10.0000294.figures.online.f1_1.jpeg?itok=4_PdGzz6" width="100" height="56" alt="Carbon nanotube-based filter" /> <p>Wednesday, December 4, 2019</p> <p><img alt="Carbon nanotube-based filter" height="540" src="/institute-for-quantum-computing/sites/ca.institute-for-quantum-computing/files/uploads/images/10.0000294.figures.online.f1_0.jpeg" width="960" /></p> 12011 Two updates https://www.scottaaronson.com/blog/?p=4439 Shtetl-Optimized urn:uuid:53ecbbbb-3c94-8d59-7f1e-9513fe609e73 Mon, 02 Dec 2019 15:31:12 +0000 Two weeks ago, I blogged about the claim of Ohad Keller and Nathan Klein to have proven the Aaronson-Ambainis Conjecture. Alas, Keller and Klein tell me that they&#8217;ve now withdrawn their preprint (though it may take another day for that to show up on the arXiv), because of what looks for now like a fatal [&#8230;] <ol><li>Two weeks ago, I <a href="https://www.scottaaronson.com/blog/?p=4414">blogged about</a> the <a href="https://arxiv.org/abs/1911.03748">claim</a> of Ohad Keller and Nathan Klein to have proven the Aaronson-Ambainis Conjecture. Alas, Keller and Klein tell me that they&#8217;ve now withdrawn their preprint (though it may take another day for that to show up on the arXiv), because of what looks for now like a fatal flaw, in Lemma 5.3, discovered by Paata Ivanishvili. (My own embarrassment over having missed this flaw is <em>slightly</em> mitigated by most of the experts in discrete Fourier analysis having missed it as well!) Keller and Klein are now working to fix the flaw, and I wholeheartedly wish them success.</li><li>In unrelated news, I was saddened to read that <a href="https://en.wikipedia.org/wiki/Virgil_Griffith">Virgil Griffith</a>&#8212;cryptocurrency researcher, former Integrated Information Theory researcher, and <a href="https://www.scottaaronson.com/blog/?p=1893">onetime contributor to <em>Shtetl-Optimized</em></a>&#8212;was <a href="https://www.forbes.com/sites/jasonbrett/2019/11/29/us-authorities-arrest-virgil-griffith-for-teaching-cryptocurrency-and-blockchain/#1a19647142cb">arrested at LAX</a> for having traveled to North Korea to teach the DPRK about cryptocurrency, against the admonitions of the US State Department. I didn&#8217;t know Virgil well, but I did meet him at least once, and I liked <a href="http://www.scottaaronson.com/response-p1.pdf">his</a> <a href="http://www.scottaaronson.com/response-p2.pdf">essays</a> for this blog about how, after spending years studying IIT under Giulio Tononi himself, he became disillusioned with many aspects of it and evolved to a position not far from mine (though not identical either).<br>Personally, I despise the North Korean regime for the obvious reasons&#8212;I regard it as not merely evil, but <em>cartoonishly</em> so&#8212;and I&#8217;m mystified by Virgil&#8217;s <a href="https://twitter.com/nicksdjohnson/status/1201212127945605122">apparently sincere belief</a> that he could bring peace between the North and South by traveling to North Korea to give a lecture about blockchain. Yet, however world-historically naïve he may have been, his intentions appear to have been good. More pointedly&#8212;and here I&#8217;m asking not in a legal sense but in a human one&#8212;if giving aid and comfort to the DPRK is treasonous, then isn&#8217;t the current occupant of the Oval Office a million times guiltier of that particular treason (to say nothing of others)? It&#8217;s like, what does &#8220;treason&#8221; even mean anymore? In any case, I hope some plea deal or other arrangement can be worked out that won&#8217;t end Virgil&#8217;s productive career.</li></ol> <p></p> Announcements Complexity Nerd Interest Scott Toward more efficient computing, with magnetic waves https://www.sciencedaily.com/releases/2019/11/191128172218.htm Quantum Computers News -- ScienceDaily urn:uuid:d24b8497-aa16-90b1-2211-63d5b62f3eb7 Thu, 28 Nov 2019 22:22:18 +0000 Researchers have devised a novel circuit design that enables precise control of computing with magnetic waves -- with no electricity needed. The advance takes a step toward practical magnetic-based devices, which have the potential to compute far more efficiently than electronics. Building a better battery with machine learning https://www.sciencedaily.com/releases/2019/11/191127090232.htm Quantum Computers News -- ScienceDaily urn:uuid:b4d4d699-04d9-971e-1f92-d0e705ac2fba Wed, 27 Nov 2019 14:02:32 +0000 Researchers have turned to the power of machine learning and artificial intelligence to dramatically accelerate battery discovery. Guest post by Greg Kuperberg: Archimedes’ other principle and quantum supremacy https://www.scottaaronson.com/blog/?p=4432 Shtetl-Optimized urn:uuid:32965ca0-20f0-93d2-2186-498d72855932 Tue, 26 Nov 2019 20:50:50 +0000 Scott&#8217;s Introduction: Happy Thanksgiving! Please join me in giving thanks for the beautiful post below, by friend-of-the-blog Greg Kuperberg, which tells a mathematical story that stretches from the 200s BC all the way to Google&#8217;s quantum supremacy result last month. Archimedes&#8217; other principle and quantum supremacy by Greg Kuperberg Note: UC Davis is hiring in [&#8230;] <p><strong>Scott&#8217;s Introduction:</strong> Happy Thanksgiving! Please join me in giving thanks for the beautiful post below, by friend-of-the-blog <a href="https://www.math.ucdavis.edu/~greg/">Greg Kuperberg</a>, which tells a mathematical story that stretches from the 200s BC all the way to Google&#8217;s quantum supremacy result last month.</p> <h2>Archimedes&#8217; other principle and quantum supremacy</h2> <p>by Greg Kuperberg</p> <p><strong>Note:</strong> UC Davis is <a href="https://recruit.ucdavis.edu/JPF03248">hiring in CS theory</a>! Scott offered me free ad space if I wrote a guest post, so here we are. The position is in all areas of CS theory, including QC theory although the search is not limited to that.</p> <p>In this post, I wear the hat of a pure mathematician in a box provided by Archimedes. I thus set aside what everyone else thinks is important about Google&#8217;s 53-qubit quantum supremacy experiment, that it is a dramatic milestone in quantum computing technology. That&#8217;s only news about the physical world, whose significance pales in comparison to the Platonic world of mathematical objects. In my happy world, I like quantum supremacy as a demonstration of a beautiful coincidence in mathematics that has been known for more than 2000 years in a special case. The single-qubit case was discovered by Archimedes, duh. As Scott mentions in <a href="https://www.amazon.com/Quantum-Computing-since-Democritus-Aaronson/dp/0521199565/ref=sr_1_1?keywords=quantum+computing+since+democritus&amp;qid=1574801358&amp;sr=8-1"><em>Quantum Computing Since Democritus</em></a>, Bill Wootters stated the general result in a <a href="https://link.springer.com/article/10.1007/BF01883491">1990 paper</a>, but Wootters credits a <a href="https://link.springer.com/article/10.1007/BF01019475">1974 paper</a> by the Czech physicist Stanislav Sýkora. I learned of it in the substantially more general context of symplectic geometric that mathematicians developed independently between Sýkora&#8217;s prescient paper and Wootters&#8217; more widely known citation. Much as I would like to clobber you with highly abstract mathematics, I will wait for some other time.</p> <p>Suppose that you pick a pure state \(|\psi\rangle\) in the Hilbert space \(\mathbb{C}^d\) of a \(d\)-dimensional qudit, and then make many copies and fully measure each one, so that you sample many times from some distribution \(\mu\) on the \(d\) outcomes. You can think of such a distribution \(\mu\) as a classical randomized state on a digit of size \(d\). The set of all randomized states on a \(d\)-digit makes a \((d-1)\)-dimensional simplex \(\Delta^{d-1}\) in the orthant \(\mathbb{R}_{\ge 0}^d\). The coincidence is that if \(|\psi\rangle\) is uniformly random in the unit sphere in \(\mathbb{C}^d\), then \(\mu\) is uniformly random in \(\Delta^{d-1}\). I will call it the Copenhagen map, since it expresses the Copenhagen interpretation of quantum mechanics that amplitudes yield probabilities. Here is a diagram of the Copenhagen map of a qutrit, except with the laughable simplification of the 5-sphere in \(\mathbb{C}^3\) drawn as a 2-sphere. </p> <figure class="wp-block-image"><img src="https://www.scottaaronson.com/f1-qutrit.png" alt=""/></figure> <p>If you pretend to be a bad probability student, then you might not be surprised by this coincidence, because you might suppose that all probability distributions are uniform other than treacherous exceptions to your intuition. However, the principle is certainly not true for a &#8220;rebit&#8221; (a qubit with real amplitudes) or for higher-dimensional &#8220;redits.&#8221; With real amplitudes, the probability density goes to infinity at the sides of the simplex \(\Delta^{d-1}\) and is even more favored at the corners. It also doesn&#8217;t work for mixed qudit states; the projection then favors the middle of \(\Delta^{d-1}\). </p> <h3>Archimedes&#8217; theorem</h3> <p> The theorem of Archimedes is that a natural projection from the unit sphere to a circumscribing vertical cylinder preserves area. The projection is the second one that you might think of: Project radially from a vertical axis rather than radially in all three directions. Since Archimedes was a remarkably prescient mathematician, he was looking ahead to the Bloch sphere of pure qubit states \(|\psi\rangle\langle\psi|\) written in density operator form. If you measure \(|\psi\rangle\langle\psi|\) in the computational basis, you get a randomized bit state \(\mu\) somewhere on the interval from guaranteed 0 to guaranteed 1. </p> <figure class="wp-block-image"><img src="https://www.scottaaronson.com/f2-bloch.png" alt=""/></figure> <p>This transformation from a quantum state to a classical randomized state is a linear projection to a vertical axis. It is the same as Archimedes&#8217; projection, except without the angle information. It doesn&#8217;t preserve dimension, but it does preserve measure (area or length, whatever) up to a factor of \(2\pi\). In particular, it takes a uniformly random \(|\psi\rangle\langle\psi|\) to a uniformly random \(\mu\).</p> <p>Archimedes&#8217; projection is also known as the Lambert cylindrical map of the world. This is the map that squishes Greenland along with the top of North America and Eurasia to give them proportionate area. </p> <figure class="wp-block-image"><img src="https://www.scottaaronson.com/f3-lambert.jpg" alt=""/></figure> <p>(I forgive Lambert if he didn&#8217;t give prior credit to Archimedes. There was no Internet back then to easily find out who did what first.) Here is a calculus-based proof of Archimedes&#8217; theorem: In spherical coordinates, imagine an annular strip on the sphere at a polar angle of \(\theta\). (The polar angle is the angle from vertical in spherical coordinates, as depicted in red in the Bloch sphere diagram.) The strip has a radius of \(\sin\theta\), which makes it shorter than its unit radius friend on the cylinder. But it&#8217;s also tilted from vertical by an angle of \(\frac{\pi}2-\theta\), which makes it wider by a factor of \(1/(\sin \theta)\) than the height of its projection onto the \(z\) axis. The two factors exactly cancel out, making the area of the strip exactly proportional to the length of its projection onto the \(z\) axis. This is a coincidence which is special to the 2-sphere in 3 dimensions. As a corollary, we get that the surface area of a unit sphere is \(4\pi\), the same as an open cylinder with radius 1 and height 2. If you want to step through this in even more detail, Scott mentioned to me an <a href="https://www.youtube.com/watch?v=GNcFjFmqEc8">action video</a> which is vastly spiffier than anything that I could ever make.</p> <p>The projection of the Bloch sphere onto an interval also shows what goes wrong if you try this with a rebit. The pure rebit states &#8212; again expressed in density operator form \(|\psi\rangle\langle\psi|\) are a great circle in the Bloch sphere. If you linearly project a circle onto an interval, then the length of the circle is clearly bunched up at the ends of the interval and the projected measure on the interval is not uniform. </p> <h3>Sýkora&#8217;s generalization</h3> <p> It is a neat coincidence that the Copenhagen map of a qubit preserves measure, but a proof that relies on Archimedes&#8217; theorem seems to depend on the special geometry of the Bloch sphere of a qubit. That the higher-dimensional Copenhagen map also preserves measure is downright eerie. Scott challenged me to write an intuitive explanation. I remembered two different (but similar) proofs, neither of which is original to me. Scott and I disagree as to which proof is nicer.</p> <p>As a first step of the first proof, it is easy to show that the Copenhagen map \(p = |z|^2\) for a single amplitude \(z\) preserves measure as a function from the complex plane \(\mathbb{C}\) to the ray \(\mathbb{R}_{\ge 0}\). The region in the complex numbers \(\mathbb{C}\) where the length of \(z\) is between \(a\) and \(b\), or \(a \le |z| \le b\), is \(\pi(b^2 &#8211; a^2)\). The corresponding interval for the probability is \(a^2 \le p \le b^2\), which thus has length \(b^2-a^2\). That&#8217;s all, we&#8217;ve proved it! More precisely, the area of any circularly symmetric region in \(\mathbb{C}\) is \(\pi\) times the length of its projection onto \(\mathbb{R}_{\ge 0}\). </p> <figure class="wp-block-image"><img src="https://www.scottaaronson.com/f4-washer.png" alt=""/></figure> <p>The second step is to show the same thing for the Copenhagen map from the \(d\)-qudit Hilbert space \(\mathbb{C}^d\) to the \(d\)-digit orthant \(\mathbb{R}_{\ge 0}^d\), again without unit normalization. It&#8217;s also measure-preserving, up to a factor of \(\pi^d\) this time, because it&#8217;s the same thing in each coordinate separately. To be precise, the volume ratio holds for any region in \(\mathbb{C}^d\) that is invariant under separately rotating each of the \(d\) phases. (Because you can approximate any such region with a union of products of thin annuli.)</p> <p>The third and final step is the paint principle for comparing surface areas. If you paint the hoods of two cars with the same thin layer of paint and you used the same volume of paint for each one, then you can conclude that the two car hoods have nearly same area. In our case, the Copenhagen map takes the region \[ 1 \le |z_0|^2 + |z_1|^2 + \cdots + |z_{d-1}|^2 \le 1+\epsilon \] in \(\mathbb{C}^d\) to the region \[ 1 \le p_0 + p_1 + \cdots + p_{d-1} \le 1+\epsilon \] in the orthant \(\mathbb{R}_{\ge 0}^d\). The former is the unit sphere \(S^{2d-1}\) in \(\mathbb{C}^d\) painted to a thickness of roughly \(\epsilon/2\). The latter is the probability simplex \(\Delta^{n-1}\) painted to a thickness of exactly \(\epsilon\). Taking the limit \(\epsilon \to 0\), the Copenhagen map from \(S^{2d-1}\) to \(\Delta^{n-1}\) preserves measure up to a factor of \(2\pi^n\).</p> <p>You might wonder &#8220;why&#8221; this argument works even if you accept that it does work. The key is that the exponent 2 appears in two different ways: as the dimension of the complex numbers, and as the exponent used to set probabilities and define spheres. If we try the same argument with real amplitudes, then the volume between &#8220;spheres&#8221; of radius \(a\) and \(b\) is just \(2(b-a)\), which does not match the length \(b^2-a^2\). The Copenhagen map for a single real amplitude is the parabola \(p = x^2\), which clearly distorts length since it is not linear. The higher-dimensional real Copenhagen map similarly distorts volumes, whether or not you restrict to unit-length states.</p> <p>If you&#8217;re a bitter-ender who still wants Archimedes&#8217; theorem for real amplitudes, then you might consider the variant formula \(p = |x|\) to obtain a probability \(p\) from a &#8220;quantum amplitude&#8221; \(x\). Then the &#8220;Copenhagen&#8221; map does preserve measure, but for the trivial reason that \(x = \pm p\) is not really a quantum amplitude, it is a probability with a vestigial sign. Also the unit &#8220;sphere&#8221; in \(\mathbb{R}^d\) is not really a sphere in this theory, it is a hyperoctahedron. The only &#8220;unitary&#8221; operators that preserve the unit hyperoctahedron are signed permutation matrices. You can only use them for reversible classical computing or symbolic dynamics; they don&#8217;t have the strength of true quantum computing or quantum mechanics.</p> <p>The fact that the Copenhagen map preserves measure also yields a bonus calculation of the volume of the unit ball in \(2d\) real dimensions, if we interpret that as \(d\) complex dimensions. The ball \[ |z_0|^2 + |z_1|^2 + \cdots + |z_{d-1}|^2 \le 1 \] in \(\mathbb{C}^d\) is sent to a different simplex \[ p_0 + p_1 + \cdots + p_{d-1} \le 1 \] in \(\mathbb{R}_{\ge 0}^d\). If we recall that the volume of a \(d\)-dimensional pyramid is \(\frac1d\) times base times height and calculate by induction on \(d\), we get that this simplex has volume \(\frac1{d!}\). Thus, the volume of the \(2d\)-dimensional unit ball is \(\frac{\pi^d}{d!}\).</p> <p>You might ask whether the volume of a \(d\)-dimensional unit ball is always \(\frac{\pi^{d/2}}{(d/2)!}\) for both \(d\) even and odd. The answer is yes if we interpret factorials using the gamma function formula \(x! = \Gamma(x+1)\) and look up that \(\frac12! = \Gamma(\frac32) = \frac{\sqrt{\pi}}2\). The gamma function was discovered by Euler as a solution to the question of defining fractional factorials, but the notation \(\Gamma(x)\) and the cumbersome shift by 1 is due to Legendre. Although Wikipedia says that no one knows why Legendre defined it this way, I wonder if his goal was to do what the Catholic church later did for itself in 1978: It put a Pole at the origin.</p> <p>(Scott wanted to censor this joke. In response, I express my loyalty to my nation of birth by quoting the opening of the Polish national anthem: &#8220;Poland has not yet died, so long as we still live!&#8221; I thought at first that Stanislav Sýkora is Polish since Stanisław and Sikora are both common Polish names, but his name has Czech spelling and he is Czech. Well, the Czechs are cool too.)</p> <p>Sýkora&#8217;s 1974 proof of the generalized Archimedes&#8217; theorem is different from this one. He calculates multivariate moments of the space of unit states \(S^{2d-1} \subseteq \mathbb{C}^d\), and confirms that they match the moments in the probability simplex \(\Delta^{d-1}\). There are inevitably various proofs of this result, and I will give another one. </p> <h3>Another proof, and quantum supremacy</h3> <p>There is a well-known and very useful algorithm to generate a random point on the unit sphere in either \(\mathbb{R}^d\) or \(\mathbb{C}^d\), and a similar algorithm to generate a random point in a simplex. In the former algorithm, we make each real coordinate \(x\) into an independent Gaussian random variable with density proportional to \(e^{-x^2}\;dx\), and then rescale the result to unit length. Since the exponents combine as \[ e^{-x_0^2}e^{-x_1^2}\cdots e^{-x_{d-1}^2} = e^{-(x_0^2 + x_1^2 + \cdots + x_{d-1}^2)}, \] we learn that the total exponent is spherically symmetric. Therefore after rescaling, the result is a uniformly random point on the unit sphere \(S^{d-1} \subseteq \mathbb{R}^d\). Similarly, the other algorithm generates a point in the orthant \(\mathbb{R}_{\ge 0}^d\) by making each real coordinate \(p \ge 0\) an independent random variable with exponential distribution \(e^{-p}\;dp\). This time we rescale the vector until its sum is 1. This algorithm likewise produces a uniformly random point in the simplex \(\Delta^{d-1} \subseteq \mathbb{R}_{\ge 0}^d\) because the total exponent of the product \[ e^{-p_0}e^{-p_1}\cdots e^{-p_{d-1}} = e^{-(p_0 + p_1 + \cdots + p_{d-1})} \] only depends on the sum of the coordinates. Wootters describes both of these algorithms in his 1990 paper, but instead of relating them to give his own proof of the generalized Archimedes&#8217; theorem, he cites Sýkora.</p> <p>The gist of the proof is that the Copenhagen map takes the Gaussian algorithm to the exponential algorithm. Explicitly, the Gaussian probability density for a single complex amplitude \[ z = x+iy = re^{i\theta} \] can be converted from Cartesian to polar coordinate as follows: \[ \frac{e^{-|z|^2}\;dx\;dy}{\pi} = \frac{e^{-r^2}r\;dr\;d\theta}{\pi}. \] I have included the factor of \(r\) that is naturally present in an area integral in polar coordinates. We will need it, and it is another way to see that the theorem relies on the fact that the complex numbers are two-dimensional. To complete the proof, we substitute \(p = r^2\) and remember that \(dp = 2r\;dr\), and then integrate over \(\theta\) (trivially, since the integrand does not depend on \(\theta\)). The density simplifies to \(e^{-p}\;dp\), which is exactly the exponential distribution for a real variable \(p \ge 0\). Since the Copenhagen map takes the Gaussian algorithm to the exponential algorithm, and since each algorithm produces a uniformly random point, the Copenhagen map must preserve uniform measure. (Scott likes this proof better because it is algorithmic, and because it is probabilistic.)</p> <p>Now about quantum supremacy. You might think that a random chosen quantum circuit on \(n\) qubits produces a nearly uniformly random quantum state \(|\psi\rangle\) in their joint Hilbert space, but it&#8217;s not quite not that simple. When \(n=53\), or otherwise as \(n \to \infty\), a manageable random circuit is not nearly creative enough to either reach or approximate most of the unit states in the colossal Hilbert space of dimension \(d = 2^n\). The state \(|\psi\rangle\) that you get from (say) a polynomial-sized circuit resembles a fully random state in various statistical and computational respects, both proven and conjectured. As a result, if you measure the qubits in the computational basis, you get a randomized state on \(n\) bits that resembles a uniformly random point in \(\Delta^{2^n-1}\).</p> <p>If you choose \(d\) probabilities, and if each one is an independent exponential random variable, then the law of large numbers says that the sum (which you use for rescaling) is close to \(d\) when \(d\) is large. When \(d\) is really big like \(2^{53}\), a histogram of the probabilities of the bit strings of a supremacy experiment looks like an exponential curve \(f(p) \propto e^{-pd}\). In a sense, the statistical distribution of the bit strings is almost the same almost every time, independent of which random quantum circuit you choose to generate them. The catch is that the position of any given bit string does depend on the circuit and is highly scrambled. I picture it in my mind like this: </p> <figure class="wp-block-image"><img src="https://www.scottaaronson.com/f5-samples.png" alt=""/></figure> <p> It is thought to be computationally intractable to calculate where each bit string lands on this exponential curve, or even where just one of them does. (The exponential curve is attenuated by noise in the actual experiment, but it&#8217;s the same principle.) That is one reason that random quantum circuits are supreme.</p> <p></p> Quantum Scott Milestone in quantum standardization https://www.sciencedaily.com/releases/2019/11/191125173512.htm Quantum Computers News -- ScienceDaily urn:uuid:bb04a075-5033-7965-a83d-f52b02faa188 Mon, 25 Nov 2019 22:35:12 +0000 Researchers have developed a method that could pave the way to establishing universal standards for measuring the performance of quantum computers. The new method, called cycle benchmarking, allows researchers to assess the potential of scalability and to compare one quantum platform against another. Ultrafast quantum simulations: A new twist to an old approach https://www.sciencedaily.com/releases/2019/11/191125120951.htm Quantum Computers News -- ScienceDaily urn:uuid:32ba3f10-f6ea-3ba4-9674-b781404e5b47 Mon, 25 Nov 2019 17:09:51 +0000 Billions of tiny interactions occur between thousands of particles in every piece of matter in the blink of an eye. Simulating these interactions in their full dynamics was said to be elusive but has now been made possible. Benchmarking scalability and performance of quantum computers https://uwaterloo.ca/institute-for-quantum-computing/news/benchmarking-scalability-and-performance-quantum-computers Institute for Quantum Computing urn:uuid:855a41c2-7f05-f641-da54-724917a85329 Mon, 25 Nov 2019 00:00:00 +0000 <img typeof="foaf:Image" src="https://uwaterloo.ca/institute-for-quantum-computing/sites/ca.institute-for-quantum-computing/files/styles/thumbnail/public/uploads/images/29617650528_7b1c8d04d1_o_1.jpg?itok=SA_Mwojx" width="100" height="67" alt="IQC faculty members Joel Wallman and Joseph Emerson at the offices of Quantum Benchmark" /> <p>Monday, November 25, 2019</p> <p class="highlight">Researchers at the Institute for Quantum Computing (IQC) have demonstrated a new method, called cycle benchmarking, to assess scalability and compare capabilities of different quantum computer platforms.</p> <p><span class="MsoIntenseEmphasis"><span>The finding leads the way towards establishing standards for quantum computing performance and strengthens the global effort to build a large-scale, practical quantum computer. </span></span></p> 12011 New twist in quest to develop understanding of time crystalline behavior https://www.sciencedaily.com/releases/2019/11/191121121807.htm Quantum Computers News -- ScienceDaily urn:uuid:2dbc6cfe-92b9-b71d-83be-c0ecb901c992 Thu, 21 Nov 2019 17:18:07 +0000 The quest to develop the understanding for time crystalline behaviour in quantum systems has taken a new, exciting twist. A super-fast 'light switch' for future cars and computers https://www.sciencedaily.com/releases/2019/11/191120131327.htm Quantum Computers News -- ScienceDaily urn:uuid:91dc0228-20df-6376-7e3a-58a990ae387c Wed, 20 Nov 2019 18:13:27 +0000 Switching light beams quickly is important in many technological applications. Researchers have now developed an 'electro-opto-mechanical' switch for light beams that is considerably smaller and faster than current models. This is relevant for applications such as self-driving cars and optical quantum technologies. Artificial intelligence algorithm can learn the laws of quantum mechanics https://www.sciencedaily.com/releases/2019/11/191119105457.htm Quantum Computers News -- ScienceDaily urn:uuid:f86725cc-c07b-39ed-63de-b6adfbc8ca47 Tue, 19 Nov 2019 15:54:57 +0000 Artificial intelligence can be used to predict molecular wave functions and the electronic properties of molecules. This innovative AI method could be used to speed-up the design of drug molecules or new materials. Quantum light improves sensitivity of biological measurements https://www.sciencedaily.com/releases/2019/11/191118152411.htm Quantum Computers News -- ScienceDaily urn:uuid:4d9a3a28-768d-88e4-5076-3855603ec80c Mon, 18 Nov 2019 20:24:11 +0000 In a new study, researchers showed that quantum light can be used to track enzyme reactions in real time. The work brings together quantum physics and biology in an important step toward the development of quantum sensors for biomedical applications. Kick-starting Moore's Law? New 'synthetic' method for making microchips could help https://www.sciencedaily.com/releases/2019/11/191118140332.htm Quantum Computers News -- ScienceDaily urn:uuid:93b43a4a-0788-ea32-1681-16bbd6a12011 Mon, 18 Nov 2019 19:03:32 +0000 Researchers have developed a new method for producing atomically-thin semiconducting crystals that could one day enable more powerful and compact electronic devices.