Quantum

Event recap: How will quantum computing shape the future of AI?

leah — Fri, 23 Oct 2020 17:40:31 +0000

From Center for Data Innovation, Oct. 23, 2020: Fermilab Deputy Director Joe Lykken participates in a panel discussion on the impact quantum computing will have on AI and which sectors might benefit the most from their marriage. A video of the discussion is available in the post.

Extreme events in quantum cascade lasers

Fri, 23 Oct 2020 16:31:11 +0000

Based on a quantum cascade laser (QCL) emitting mid-infrared light, the researchers developed a basic optical neuron system operating 10,000× faster than biological neurons.

Optical wiring for large quantum computers

Thu, 22 Oct 2020 13:39:50 +0000

Researchers have demonstrated a new technique for carrying out sensitive quantum operations on atoms. In this technique, the control laser light is delivered directly inside a chip. This should make it possible to build large-scale quantum computers based on trapped atoms.

Daniel Harlow awarded Packard Foundation Fellowship

Sandi Miller | Department of Physics — Tue, 20 Oct 2020 16:01:00 +0000

The David and Lucile Packard Foundation has announced that Daniel Harlow, assistant professor of physics and a researcher at the MIT Center for Theoretical Physics, has been named a Packard Fellow for Science and Engineering. The Packard Foundation Fellowships are one of the most prestigious and well-funded non-governmental awards for early-career scientists.

Each year, the foundation invites 50 university presidents to nominate two early-career professors each from their institutions; from those 100 nominees, an advisory panel of distinguished scientists and engineers select the fellows, who receive individual grants of $875,000 over five years. The 2020 class comprises 20 fellows.

“Daniel Harlow has emerged as a leader in formal field theory and continues MIT’s great tradition in formal theory," says Peter Fisher, professor and head of MIT’s Department of Physics.

Harlow researches black holes by combining quantum mechanics and Einstein's general relativity. The Packard Foundation recognized Harlow’s use of ideas from quantum computation to generate new insights about both black holes and quantum computers.

“Understanding the quantum properties of black holes has been one of the great challenges in physics for the last five decades, and in recent years we have learned that it is closely related to many other interesting problems,” says Harlow. “In particular there is an ongoing interplay with the theories of condensed matter systems and quantum computers. It is my hope that with this fellowship my group and I will be able to make progress on all of these fronts, helping to create a new kind of physics where the old boundaries between subfields are forgotten and any interesting problem is fair game.”

Harlow is a co-discoverer of a close connection between the anti-de Sitter/conformal field theory (AdS/CFT) correspondence, a relationship between certain theories of quantum gravity and quantum field theories, and the theory of quantum error correcting codes. With Kavli Institute for the Physics and Mathematics of the Universe and Caltech scientist Hirosi Ooguri, he also recently developed a new understanding of symmetry in particle physics and gravity, with which they were able to prove that no global symmetry can exist on the gravity side of the AdS/CFT correspondence.

Harlow was a postdoc at Princeton and Harvard universities before joining MIT in July 2017. He earned a doctorate in physics from Stanford University in 2012, and received his bachelor’s degree in physics and mathematics from Columbia University in 2006.

Harlow was awarded the 2019 New Horizons in Physics Prize "for fundamental insights about quantum information, quantum field theory, and gravity,” and is a member of the Simons Foundation’s "It from Qubit" Collaboration on Quantum Fields, Gravity, and Information.

“I am thrilled to be receiving a Packard Fellowship!” says Harlow. “It is a great honor to be entrusted with this responsibility, and I hope I will be able to live up to the high standards of my predecessors.”

Past Packard fellows have gone on to receive such honors as the Nobel Prize in chemistry and physics, the Fields Medal, the Alan T. Waterman Award, MacArthur Fellowships, and elections to the National Academies.

IQC faculty honoured with President’s Excellence in Research awards

12011 — Tue, 20 Oct 2020 00:00:00 +0000

Tuesday, October 20, 2020

Four faculty members at the Institute for Quantum Computing received President’s Excellence in Research awards for their research achievements that were recognized by national or international foundations, associations and institutions.

David Gosset, Christine Muschik, Rajibul Islam and Raymond Laflamme were among 125 educators and researchers who were honoured for receiving President’s Excellence in Teaching and Research awards in an online celebration October 7.

Physicist joins international effort to unveil the behavior of 'strange metals'

Mon, 19 Oct 2020 14:34:45 +0000

Physicists have solved the puzzle of the NFL behavior in interacting electrons systems, and provided a protocol for the establishment of new paradigms in quantum metals, through quantum many-body computation and analytical calculations.

Quantum engines with entanglement as fuel?

Mon, 19 Oct 2020 13:01:25 +0000

It's still more science fiction than science fact, but perfect energy efficiency may be one step closer due to new research by physicists.

Afterlife for Chemistry Simulations in Near-term Quantum Computers

dougfinke1 — Sun, 18 Oct 2020 23:57:04 +0000

By Andre, Saraiva, UNSW Before full quantum error correction is achieved, the range of problems that can be solved with the current small, noisy quantum computers is very limited. Among the most exciting applications is the computer simulation of molecules, with potential applications for drug design and discovery of special materials. These algorithms can use [...]

Ask Not What Quantum Can Do for Machine Learning, Ask What Machine Learning Can Do for Quantum

dougfinke1 — Sun, 18 Oct 2020 00:06:32 +0000

There is a lot of research underway on quantum machine learning to understand how the use of quantum computers can speed up machine learning applications. In particular, many researchers believe that in the future quantum computers will be able to speed up training for Boltzmann machines and neural networks. However, what has not received a [...]

Design Your Own Superconducting Qubits with IBM’s Qiskit Metal

dougfinke1 — Sat, 17 Oct 2020 19:27:45 +0000

Quantum Chip Design Flow and Where Qiskit Metal Fits In. Credit: IBM IBM is releasing an open source computer aided design (CAD) program called Qiskit Metal that will allow a user to layout and analysis a superconducting qubit. The program will include a library of elements such as transmon qubits and coplanar resonators and includes [...]

Fujitsu Partners with International Research Institutions for Quantum Research

dougfinke1 — Fri, 16 Oct 2020 22:38:39 +0000

Fujitsu Labs announced it will establish three new collaborations with academic institutions to research different topics in quantum computing. The first is a collaboration with RIKEN and the University of Tokyo to study superconducting quantum computers. The second is a project with TU Delft to research quantum computers built with diamond-based spin qubits. And the [...]

Researchers discover a uniquely quantum effect in erasing information

Fri, 16 Oct 2020 14:09:26 +0000

Researchers have discovered a uniquely quantum effect in erasing information that may have significant implications for the design of quantum computing chips. Their surprising discovery brings back to life the paradoxical 'Maxwell's demo', which has tormented physicists for over 150 years.

Airbus Announces Five Finalists to their Quantum Computing Challenge

dougfinke1 — Thu, 15 Oct 2020 04:18:20 +0000

At the Q2B Conference in December 2018, Airbus announced a Quantum Computing Challenge to see whether any individuals or teams could help them find quantum computing solutions to five different computational problems they faced. Since then, they attracted interest from over 800 individuals, held webinars to clarify the problems and received proposals from 36 different [...]

Temperature evolution of impurities in a quantum gas

Wed, 14 Oct 2020 15:46:54 +0000

A new theoretical study advances our understanding of the role of thermodynamics in the 'quantum impurity' problem, which studies the behavior of deliberately introduced atoms (ie, 'impurities') that behave as particularly 'clean' quasiparticles within a background atomic gas, allowing a controllable 'perfect test bed' study of quantum correlations.

Bringing a power tool from math into quantum computing

Wed, 14 Oct 2020 15:46:15 +0000

The Fourier transform is a mathematical operation essential to virtually all fields of physics and engineering. Although there already exists an algorithm that computes the Fourier transform in quantum computers, it is not versatile enough for many practical applications. In a recent study, scientists tackle this problem by designing a novel quantum circuit that calculates the Fourier transform in a much quicker, versatile, and more efficient way.

Vote in person if you can

Scott — Wed, 14 Oct 2020 01:35:53 +0000

[If you’re not American, or you’re American but a masochist who enjoys the current nightmare, this post won’t be relevant to you—sorry!]

Until recently, this blog had a tagline that included “HOLD THE NOVEMBER US ELECTION BY MAIL.” So I thought I should warn readers that circumstances have changed in ways that have important practical implications over the next few weeks. It’s no longer that we don’t know whether Trump and Pence will acknowledge a likely loss—rather, it’s that we know they won’t. They were repeatedly asked; we all heard their answers.

That means that the best case, the ideal scenario, is already without precedent in the country’s 240-year history. It’s a president who never congratulates the winner, who refuses to meet him or coordinate a transfer of power, who skips the inauguration, and who’s basically dragged from the White House on January 20, screaming to his supporters (and continuing to scream until his dying breath) that the election was faked.

As I said, that banana-republic outcome is now the best case. But it’s also plausible that Trump simply declares himself the winner on election night, because the mail-in votes, urban votes, yet-to-be-counted votes, or any other votes that trend the wrong way are fake; social media and the Murdoch press amplify this fantasy; Trump calls on Republican-controlled state legislatures to set aside the “rigged” results and appoint their own slates of electors; the legislatures dutifully comply; and the Supreme Court A-OKs it all. If you think none of that could happen, read this Atlantic article from a few weeks ago, carefully to the end, and be more terrified than you’ve ever been in your life. And don’t pretend that you know what would happen next.

I know, I know, I’m mentally ill, it’s Trump Derangement Syndrome, I see Nazis behind every corner just because they killed most of my relatives, a little global pandemic here and economic collapse there and riots and apocalyptic fires and resurgent fascism and I act as though it’s the whole world coming to an end. A few months from now, after everything has gone swimmingly, this post will still be here and you can come back and tell me how crazy I was. I accept that risk.

For now, though, the best chance to avert a catastrophe is for Trump not merely to lose, but lose in a landslide that’s already clear by election night. Which means: as Michelle Obama advised already in August, put on your mask, brave the virus, and vote in person if you can—especially if you live in a state that’s in play, and that won’t start tallying mail-in ballots till after election day. If your state allows it, vote early, when lines are shorter. That’s what Dana and I plan to do tomorrow; Texas going blue on election night would be one dramatic way to foreclose shenanigans. If you can’t vote in person, or if your state counts mail-in ballots earlier, then vote by mail or drop-box, but do it now, so you have a chance to fix any problems well before Election Day. I welcome other tips in the comments, from the many readers more immersed in this stuff than I am.

And if this post helped spur you in any way, please say so in the comments. It will improve my mood, thereby helping me finish my next post, which will be on the Continuum Hypothesis.

Engineers create helical topological exciton-polaritons

Tue, 13 Oct 2020 16:41:55 +0000

Researchers have created an even more exotic form of the exciton-polariton, one which has a defined quantum spin that is locked to its direction of motion. Depending on the direction of their spin, these helical topological exciton-polaritons move in opposite directions along the surface of an equally specialized type of topological insulator.

International Quantum Shorts film festival opens for entries

51 — Tue, 13 Oct 2020 00:00:00 +0000

Tuesday, October 13, 2020

Calling for films that fit quantum stories into five minutes

Can you show us the world through a quantum lens? The Quantum Shorts film festival is returning with a new call for entries. The international contest seeks films up to five minutes long that draw inspiration from the quantum world.

The Institute for Quantum Computing (IQC) is proud to once again be a scientific partner in the annual Quantum Shorts competition.

My second podcast with Lex Fridman

Scott — Mon, 12 Oct 2020 14:38:07 +0000

Here it is—enjoy!

We recorded it a month ago—outdoors (for obvious covid reasons), on a covered balcony in Austin, as it drizzled all around us. I haven’t listened to it yet. Thanks so much to Lex for his characteristically probing questions, apologies as always for my verbal tics, and here’s our first podcast for those who missed that one.

Generating photons for communication in a quantum computing system

Michaela Jarvis | Research Laboratory of Electronics — Wed, 07 Oct 2020 19:15:00 +0000

MIT researchers using superconducting quantum bits connected to a microwave transmission line have shown how the qubits can generate on demand the photons, or particles of light, necessary for communication between quantum processors.

The advance is an important step toward achieving the interconnections that would allow a modular quantum computing system to perform operations at rates exponentially faster than classical computers can achieve.

“Modular quantum computing is one technique for reaching quantum computation at scale by sharing the workload over multiple processing nodes,” says Bharath Kannan, MIT graduate fellow and first author of a paper on this topic published today in Science Advances. “These nodes, however, are generally not co-located, so we need to be able to communicate quantum information between distant locations.”

In classical computers, wires are used to route information back and forth through a processor during computation. In a quantum computer, the information itself is quantum mechanical and fragile, requiring new strategies to simultaneously process and communicate information.

“Superconducting qubits are a leading technology today, but they generally support only local interactions (nearest-neighbor or qubits very close by). The question is how to connect to qubits that are at distant locations,” says William Oliver, an associate professor of electrical engineering and computer science, MIT Lincoln Laboratory fellow, director of the Center for Quantum Engineering, and associate director of the Research Laboratory of Electronics. “We need quantum interconnects, ideally based on microwave waveguides that can guide quantum information from one location to another.”

That communication can occur via the microwave transmission line, or waveguide, as the excitations stored in the qubits generate photon pairs, which are emitted into the waveguide and then travel to two distant processing nodes. The identical photons are said to be “entangled,” acting as one system. As they travel to distant processing nodes, they can distribute that entanglement throughout a quantum network.

“We generate the entangled photons on demand using the qubits and then release the entangled state to the waveguide with very high efficiency, essentially unity,” says Oliver.

The research reported in the Science Advances paper utilizes a relatively simple technique, Kannan says.

“Our work presents a new architecture for generating photons that are spatially entangled in a very simple manner, using only a waveguide and a few qubits, which act as the photonic emitters,” says Kannan. “The entanglement between the photons can then be transferred into the processors for use in quantum communication or interconnection protocols.”

While the researchers said they have not yet implemented those communication protocols, their ongoing research is aimed in that direction.

“We did not yet perform the communication between processors in this work, but rather showed how we can generate photons that are useful for quantum communication and interconnection,” Kannan says.

Previous work by Kannan, Oliver, and colleagues introduced a waveguide quantum electrodynamics architecture using superconducting qubits that are essentially a type of artificial giant atom. That research demonstrated how such an architecture can perform low-error quantum computation and share quantum information between processors. This is accomplished by adjusting the frequency of the qubits to tune the qubit-waveguide interaction strength so the fragile qubits can be protected from waveguide-induced decoherence to perform high-fidelity qubit operations, and then readjusting the qubit frequency so the qubits are able to release their quantum information into the waveguide in the form of photons.

This paper presented the photon generation ability of the waveguide quantum electrodynamics architecture, showing that the qubits can be used as quantum emitters for the waveguide. The researchers demonstrated that quantum interference between the photons emitted into the waveguide generates entangled, itinerant photons that travel in opposite directions and can be used for long-distance communication between quantum processors.

Generating spatially entangled photons in optical systems is typically accomplished using spontaneous parametric down-conversion and photodetectors, but the generated entanglement achieved that way is generally random and therefore less useful in enabling on-demand communication of quantum information in a distributed system.

“Modularity is a key concept of any extensible system,” says Oliver. “Our goal here is to demonstrate the elements of quantum interconnects that should be useful in future quantum processors.”

Nominations Open for Wittek Quantum Prize for Open Source Software

dougfinke1 — Wed, 07 Oct 2020 15:14:57 +0000

The Quantum Open Source Foundation (QOSF) and the Unitary Fund have established a $4000 prize for an individual who has made a substantial impact on the quantum open source ecosystem. The individual may not have previously received a great deal of recognition but should receive this prize due to their enthusiastic and diligent support for [...]

Aliro Quantum Introduces Its First Software Products for Computing and Networking

dougfinke1 — Wed, 07 Oct 2020 15:11:27 +0000

Aliro Quantum, a quantum software company spun out of spun out of Harvard’s Quantum Information Science Lab in 2019, has introduced its first two products. The first is called Aliro Q.Compute (AQC) and is a development platform that will take quantum programs written in QASM, pyQuil, or other quantum languages and optimize them to run [...]

Light Rider Introduces a Secure Network Technology that Combines Li-Fi with QRNG and PQC

dougfinke1 — Tue, 06 Oct 2020 18:05:39 +0000

Light Rider has introduced two new products that use Li-Fi networking technology for communications. Li-Fi is like Wi-Fi except that it uses streams of light instead of radio waves as the transport medium. Li-Fi has some potential advantages because the communication cannot go through walls, so a hacker who is not physically present in the [...]

Scientists find evidence of exotic state of matter in candidate material for quantum computers

Mon, 05 Oct 2020 21:08:41 +0000

Using a novel technique, scientists have found evidence for a quantum spin liquid, a state of matter that is promising as a building block for the quantum computers of tomorrow.

New algorithm could unleash the power of quantum computers

Mon, 05 Oct 2020 18:08:11 +0000

A new algorithm that fast forwards simulations could bring greater use ability to current and near-term quantum computers, opening the way for applications to run past strict time limits that hamper many quantum calculations.

On the destruction of America’s best high school

Scott — Sun, 04 Oct 2020 18:59:18 +0000

[C]hildren with special abilities and skills need to be nourished and encouraged. They are a national treasure. Challenging programs for the “gifted” are sometimes decried as “elitism.” Why aren’t intensive practice sessions for varsity football, baseball, and basketball players and interschool competition deemed elitism? After all, only the most gifted athletes participate. There is a self-defeating double standard at work here, nationwide.
—Carl Sagan, The Demon-Haunted World (1996)

I’d like you to feel about the impending destruction of Virginia’s Thomas Jefferson High School for Science and Technology, the same way you might’ve felt when the Taliban threatened to blow up the Bamyan Buddhas, and then days later actually did blow them up. Or the way you felt when human negligence caused wildfires that incinerated half the koalas in Australia, or turned the San Francisco skyline into an orange hellscape. For that matter, the same way most of us felt the day Trump was elected. I’d like you to feel in the bottom of your stomach the avoidability, and yet the finality, of the loss.

For thousands of kids in the DC area, especially first- or second-generation immigrants, TJHS represented a lifeline. Score high enough on an entrance exam—something hard but totally within your control—and you could attend a school where, instead of the other kids either tormenting or ignoring you, they might teach you Lisp or the surreal number system. Where you could learn humility instead of humiliation.

When I visited TJHS back in 2012, to give a quantum computing talk, I toured the campus, chatted with students, fielded their questions, and thought: so this is the teenagerhood—the ironically normal teenagerhood—that I was denied by living someplace else. I found myself wishing that a hundred more TJHS’s, large and small, would sprout up across the country. I felt like if I could further that goal then, though the universe return to rubble, my life would’ve had a purpose.

Instead, of course, our sorry country is destroying the few such schools that exist. Stuyvesant and Bronx Science in New York, and the Liberal Arts and Science Academy here in Austin, are also under mortal threat right now. The numerous parents who moved, who arranged their lives, specifically so that these schools might later be available for “high-risk” kids were suckered.

Assuming you haven’t just emerged from 30 years in a Tibetan cave, you presumably know why this is happening. As of the Washington Post‘s Jay Matthews explains, the Fairfax County School Board is “embarrassed” to have a school that, despite all its outreach attempts, remains only 5% Black and Latino—even though, crucially, the school also happens to be only 19% White (it’s now ~75% Asian).

You might ask: so then why doesn’t TJHS just institute affirmative action, like almost every university does? It seems there’s an extremely interesting answer: they did in the 1990s, and Black and Hispanic enrollment surged. But then the verdicts of court cases, brought by right-wing groups, made the school district fear that they’d be open to lawsuits if they continued with affirmative action, so they dropped it. Now the boomerang has returned, and it’s time for a more drastic remedy: namely, to eliminate the TJHS entrance exam entirely, and replace it by a lottery for anyone whose GPA exceeds 3.5.

The trouble is, TJHS without an entrance exam is no longer TJHS. More likely than not, such a place would simply converge to become another of the thousands of schools across the US where success is based on sports, networking, and popularity. And if by some miracle it avoided that fate, still it would no longer be available to most of the kids who‘d most need it.

So yes, the district is embarrassed—note that the Washington Post writer explains it as if that’s the most obvious, natural reaction in the world—to host a school that’s regularly ranked #1 in the US, with the highest average SATs and a distinguished list of alumni. To avoid this embarrassment, the solution is (in effect) to burn the school to the ground.

In a world-historic irony, the main effect of this “solution” will be to drastically limit the number of Asian students, while drastically increasing (!!!) the number of White students. The proportion of Black and Hispanic students is projected to increase a bit but remain small. Let me say that one more time: in practice, TJHS’s move from a standardized test to a lottery will be overwhelmingly pro-White, anti-Asian, and anti-immigrant; only as a much smaller effect will it be pro-underrepresented-minority.

In spite of covid and everything else going on, hundreds of students and parents have been protesting in front of TJHS to try to prevent the school’s tragic and pointless destruction. But it sounds like TJHS’s fate might be sealed. The school board tolerated excellence for 35 more years than it wanted to; now its patience is at an end.

Some will say: sure, the end of TJHS is unfortunate, Scott, but why do you let this stuff weigh on you so heavily? This is merely another instance of friendly fire, of good people fighting the just war against racism, and in one case hitting a target that, yeah, OK, probably should’ve been spared. On reflection, though, I can accept that only insofar as I accept that it was “friendly fire” when Bolsheviks targeted kulaks, or (much more comically, less importantly, and less successfully) when Arthur Chu, Amanda Marcotte, and a thousand other woke-ists targeted me. With friendly fire like that, who needs enemy fire?

If you care about the gifted Black and Hispanic kids of Fairfax County, then like me, you should demand a change in the law to allow the reinstatement of affirmative action for them. You should acknowledge that the issue lies there and not with TJHS itself.

I don’t see how you reach the point of understanding all the facts and still wanting to dismantle TJHS, over the desperate pleas of the students and parents, without a decent helping of resentment toward the kind of student who flourishes there—without a wish to see those uppity, “fresh off the boat” Chinese and Indian grinds get dragged down to where they belong. And if you tell me that you yourself were once that type of kid—well, isn’t that more contemptible still? Aren’t you knowingly burning a bridge you crossed so that a younger generation can’t follow you, basically reassuring the popular crowd that if they’ll only accept you, then there won’t be a hundred more greasy nerds in your tow? And if, on some level, you already know these things about yourself, then the only purpose of this post has been to remind you of them.

As for the news that dominates the wires and inevitably preempts what I’ve written: I wish for his successful recovery, followed by his losing the election and spending the rest of his life in New York State prison. (And I look forward to seeing how woke Twitter summarizes the preceding statement—e.g., “Aaronson, his mask finally off, conveys well-wishes to Donald Trump”…)

Silicon Quantum Computing: What Are They Up To in the Land Down Under?

dougfinke1 — Sat, 03 Oct 2020 00:19:29 +0000

We recently had the pleasure of talking with Michelle Simmons and John Martinis about John’s new role at Silicon Quantum Computing (SQC) and SQC’s overall approach for quantum computing. John had only recently emerged a few days earlier from the mandatory traveler’s quarantine and he had only just started talking with the engineering team to [...]

IonQ Announces a 32 Qubit Ion Trap Computer with Low Qubit Gate Errors

dougfinke1 — Fri, 02 Oct 2020 00:49:39 +0000

The trick in developing a high performance quantum computer is to create one that combines a high number of qubits with a high quality level in those qubits. IonQ has been working on this for some time and their newly announced 32 qubit machine is a follow-on to their 11 qubit model which is currently [...]

Inaugural winner of Laflamme and Gregson award for women in quantum information science announced

51 — Fri, 02 Oct 2020 00:00:00 +0000

Friday, October 2, 2020

Cindy Yang is the winner of the inaugural Raymond Laflamme and Janice Gregson Graduate Scholarship for Women in Quantum Information Science.

Yang, a new Master of Applied Science student in Electrical and Computer Engineering (quantum information) has a passion for acoustic and superconducting waves who discovered quantum information science while learning how to make photonic devices. She was instantly intrigued by the possibilities that quantum research offered her.

New detector breakthrough pushes boundaries of quantum computing

Wed, 30 Sep 2020 15:42:07 +0000

A new article shows potential for graphene bolometers to become a game-changer for quantum technology.

Anna Grassellino: “Io, da Marsala a Chicago per creare un computer”

leah — Tue, 29 Sep 2020 17:47:18 +0000

From La Repubblica, Sept. 27, 2020: Intervista alla scienzata di origine marsalese che dirige il Fermilab - Fermi National Accelerator Laboratory.

Avoiding environmental losses in quantum information systems

Mon, 28 Sep 2020 16:50:12 +0000

New research has revealed how robust initial states can be prepared in quantum information systems, minimizing any unwanted transitions which lead to losses in quantum information.

To kill a quasiparticle: A quantum whodunit

Mon, 28 Sep 2020 13:37:38 +0000

Quasiparticles die young, lasting far, far less than a second. Why? A new Monash University study finds a culprit beyond the usual suspect (decay into lower energy states). Identification of the new villain--many-body dephasing--may be key to controlling quantum effects such as superconductivity and superfluidity.

Physicists develop a method to improve gravitational wave detector sensitivity

Fri, 25 Sep 2020 15:36:53 +0000

Gravitational wave detectors opened a new window to the universe by measuring the ripples in spacetime produced by colliding black holes and neutron stars, but they are ultimately limited by quantum fluctuations induced by light reflecting off of mirrors. Researchers have conducted a new experiment to explore a way to cancel this quantum backaction and improve detector sensitivity.

Spin clean-up method brings practical quantum computers closer to reality

Fri, 25 Sep 2020 15:33:49 +0000

Researchers create a quantum algorithm that removes spin contaminants while making chemical calculations on quantum computers. This allows for predictions of electronic and molecular behavior with degrees of precision not achievable with classical computers and paves the way for practical quantum computers to become a reality.

New specialization prepares grad students for growing quantum industry

12011 — Fri, 25 Sep 2020 00:00:00 +0000

Friday, September 25, 2020

The Institute for Quantum Computing (IQC), the Department of Physics and Astronomy and the Transformative Quantum Technologies Program (TQT) at the University of Waterloo announce a new Master of Science degree in Physics with a specialization in Quantum Technologies.

New possibilities for working with quantum information

Thu, 24 Sep 2020 17:53:46 +0000

The spin of particles can be manipulated by a magnetic field. This principle is the basic idea behind magnetic resonance imaging as used in hospitals. A surprising effect has now been discovered in the spins of phosphorus atoms coupled to microwaves: If the atoms are excited, they can emit a series of echoes. This opens up new ways of information processing in quantum systems.

A question of reality

Thu, 24 Sep 2020 17:53:42 +0000

Physicists have published a review that explores Bell's inequalities and his concepts of reality and explains their relevance to quantum information and its applications.

Bridging the gap between the magnetic and electronic properties of topological insulators

Thu, 24 Sep 2020 15:41:43 +0000

Scientists have shed light on the relationship between the magnetic properties of topological insulators and their electronic band structure. Their experimental results offer new insights into recent debates regarding the evolution of the band structure with temperature in these materials, which exhibit unusual quantum phenomena and are envisioned to be crucial in next-generation electronics, spintronics, and quantum computers.

La siciliana che progetta il computer quantistico più potente al mondo

leah — Tue, 22 Sep 2020 14:00:22 +0000

From Radiotelevisione Italiana Spa, Sept. 2, 2020: Anna Grassellino, 39 anni, marsalese, è stata incaricata dal governo americano di realizzare al Fermilab di Chicago il calcolatore più veloce di sempre. Il progetto prevede anche iniziative di formazione in Sicilia.

La scienziata italiana che guida gli Usa nella corsa al computer quantistico

leah — Mon, 21 Sep 2020 20:09:40 +0000

From La Repubblica, Aug. 28, 2020: Anna Grassellino, 39 anni di Marsala, coordina duecento scienziati a Chicago per realizzare un obiettivo sul quale la Cina ha investito 10 miliardi. "E' una questione di sicurezza nazionale, ma io mi occupo di scienza. Mi piace ascoltare le risposte che dà la natura alle nostre domande."

Why there is no speed limit in the superfluid universe

Mon, 21 Sep 2020 12:37:12 +0000

Physicists have established why objects moving through superfluid helium-3 lack a speed limit; exotic particles that stick to all surfaces in the superfluid. The discovery may guide applications in quantum technology, even quantum computing, where multiple research groups already aim to make use of these unusual particles.

Agent 3203.7: Guest post by Eliezer Yudkowsky

Scott — Mon, 21 Sep 2020 04:01:10 +0000

In his day, Agent 3203.7 had stopped people from trying to kill Adolf Hitler, Richard Nixon, and even, in the case of one unusually thoughtful assassin, Henry David Thoreau. But this was a new one on him.

“So…” drawled the seventh version of Agent 3203. His prosthetic hand crushed the simple 21st-century gun into fused metal and dropped it. “You traveled to the past in order to kill… of all people… Donald Trump. Care to explain why?”

The time-traveller’s eyes looked wild. Crazed. Nothing unusual. “How can you ask me that? You’re a time-traveler too! You know what he does!”

That was a surprising level of ignorance even for a 21st-century jumper. “Different timelines, kid. Some are pretty obscure. What the heck did Trump do in yours that’s worth taking your one shot at time travel to assassinate him of all people?”

“He’s destroying my world!”

Agent 3203.7 took a good look at where Donald Trump was pridefully addressing the unveiling of the Trump Taj Mahal in New Jersey, then took another good look at the errant time-traveler. “Destroying it how, exactly? Did Trump turn mad scientist in your timeline?”

“He’s President of the United States!”

Agent 3203.7 took another long stare at his new prisoner. He was apparently serious. “How did Trump become President in your timeline? Strangely advanced technology, subliminal messaging?”

“He was elected in the usual way,” the prisoner said bitterly.

Agent 3203.7 shook his head in amazement. Talk about shooting the messenger. “Kid, I doubt Trump was your timeline’s main problem.”

(thanks to Eliezer for giving me permission to reprint here)

New design principles for spin-based quantum materials

Fri, 18 Sep 2020 16:22:07 +0000

A new design criteria for enhancing the spin lifetime of a class of quantum materials could support Internet of Things devices and other resource-intensive technologies.

Usa, un’italiana a capo del progetto per il computer più potente al mondo

leah — Wed, 16 Sep 2020 20:00:08 +0000

From Affar Italiani, Aug. 28, 2020: Anna Grassellino dirigerà i lavori per la costruzione del super computer quantico. Si potrà svelare il mistero della materia oscura nell’universo

Reviewing the quantum material 'engine room'

Wed, 16 Sep 2020 13:42:35 +0000

An Australian collaboration reviews the quantum anomalous Hall effect (QAHE), one of the most fascinating and important recent discoveries in condensed-matter physics. QAHE allows zero-resistance electrical 'edge paths' in emerging quantum materials such as topological insulators, opening great potential for ultra-low energy electronics.

In a world like this one, take every ally you can get

Scott — Wed, 16 Sep 2020 07:51:47 +0000

For the past few months, I’ve alternated between periods of debilitating depression and (thankfully) longer stretches when I’m more-or-less able to work. Triggers for my depressive episodes include reading social media, watching my 7-year daughter struggle with prolonged isolation, and (especially) contemplating the ongoing apocalypse in the American West, the hundreds of thousands of pointless covid deaths, and an election in 48 days that if I didn’t know such things were impossible in America would seem likely to produce a terrifying standoff as a despot and millions of his armed loyalists refuse to cede control. Meanwhile, catalysts for my relatively functional periods have included teaching my undergrad quantum information class, Zoom calls with my students, life on Venus?!? (my guess is no, but almost entirely due to priors), learning new math (fulfilling a decades-old goal, I’m finally working my way through Paul Cohen’s celebrated proof of the independence of the Continuum Hypothesis—more about that later!).

Of course, when you feel crushed by the weight of the world’s horribleness, it improves your mood to be able even just to prick the horribleness with a pin. So I was gratified that, in response to a previous post, Shtetl-Optimized readers contributed at least $3,000, the first $2,000 of which I matched, mostly to the Biden-Harris campaign but a little to the Lincoln Project.

Alas, a commenter was unhappy with the latter:

Lincoln Project? Really? … Pushing the Overton window rightward during a worldwide fascist dawn isn’t good. I have trouble understanding why even extremely smart people have trouble with this sort of thing.

Since this is actually important, I’d like to spend the rest of this post responding to it.

For me it’s simple.

What’s the goal right now? To defeat Trump. In the US right now, that’s the prerequisite to every other sane political goal.

What will it take to achieve that goal? Turnout, energizing the base, defending the election process … but also, if possible, persuading a sliver of Trump supporters in swing states to switch sides, or at least vote third party or abstain.

Who is actually effective at that goal? Well, no one knows for sure. But while I thought the Biden campaign had some semi-decent ads, the Lincoln Project’s best stuff seems better to me, just savagely good.

Why are they effective? The answer seems obvious: for the same reason why a jilted ex is a more dangerous foe than a stranger. If anyone understood how to deprogram a Republican from the Trump cult, who would it be: Alexandria Ocasio-Cortez, or a fellow Republican who successfully broke from the cult?

Do I agree with the Lincoln Republicans about most of the “normal” issues that Americans once argued about? Not at all. Do I hold them, in part, morally responsible for creating the preconditions to the current nightmare? Certainly.

And should any of that cause me to boycott them? Not in my moral universe. If Churchill and FDR could team up with Stalin, then surely we in the Resistance can temporarily ally ourselves with the rare Republicans who chose their stated principles over power when tested—their very rarity attesting to the nontriviality of their choice.

To my mind, turning one’s back on would-be allies, in a conflict whose stakes obviously overshadow what’s bad about those allies, is simultaneously one of the dumbest and the ugliest things that human beings can do. It abandons reason for moral purity and ends up achieving neither.

UArizona collaborates on $115M effort to build quantum computer

leah — Tue, 15 Sep 2020 19:04:33 +0000

From University of Arizona, Sept. 2, 2020: Three University of Arizona researchers are involved in the Fermilab-hosted Superconducting Quantum Materials and Systems Center, which is part of a $625 million federal program to foster quantum innovation in the United States.

Single photons from a silicon chip

Tue, 15 Sep 2020 14:59:53 +0000

Quantum technology holds great promise: Quantum computers are expected to revolutionize database searches, AI systems, and computational simulations. Today already, quantum cryptography can guarantee secure data transfer, albeit with limitations. The greatest possible compatibility with current silicon-based electronics will be a key advantage. And that is precisely where physicists have made progress: The team has designed a silicon-based light source to generate single photons that propagate well in glass fibers.

Quantum computing: L’INFN, unico partner non statunitense, nel progetto USA da 115 milioni di dollari

leah — Mon, 14 Sep 2020 14:00:48 +0000

From INFN, Aug. 26, 2020: Il Department of Energy degli Stati Uniti finanzia il Superconducting Quantum Materials and Systems Center, coordinato dal Fermilab di Chicago e guidato dall’italiana Anna Grassellino. L’INFN parteciperà al progetto con il suo know-how scientifico e tecnologico, e grazie al finanziamento realizzerà una facility per dispositivi quantistici nei suoi Laboratori Nazionali del Gran Sasso.