March Meeting Quantum Computing Schedule

The APS March meeting is next week as 10000 physicists invade Portland, Oregon. I hope Powell’s bookstore has stocked their science sections well! GQI, the topical group on quantum information, sponsors a good number of sessions at the meeting including sessions with invited talks, focus sessions, and general sessions. Below the fold I’m assembling a list of quantum computing sessions, but before the fold I’d like to point out the invited sessions, which have longer speaking slots where one can actually learn more than the speakers name and research project title, that are sponsored or cosponsored by GQI (also below note the Focus sessions listed below have invited speakers)

  • Monday, March 15 8:00am-11:00am Session A8: Quantum Opto-Mechanics
    Room: Portland Ballroom 255
    (Jointly sponsored with DAMOP)
    Invited speakers: Jack Harris, Klemens Hammerer, Philipp Treutlein, Nathaniel Brahms, Keith Schwab
  • Monday, March 15 11:15am-2:15pm Session B6: Controlling Dissipation in Quantum Systems
    Room: Portland Ballroom 253
    (Jointly sponsored with DAMOP)
    Invited Speakers: Frank Verstraete, Hans Peter Buechler, Matthias Lettner, Luis A. Orozco, Sergio Boixo
  • Monday, March 15 2:30pm-5:30pm Session D4: Quantum Computer Science
    Room: Oregon Ballroom 204 Invited Speakers: Graeme Smith, Aram Harrow, Ben Reichardt, Sandy Irani, Stephanie Wehner
  • Thursday, March 18 11:15am-1:40pm Session W6: Superconducting Qubits
    Room: Portland Ballroom 253
    Invited Speakers: Radoslaw Bialczak, Franco Nori, Leonardo DiCarlo, Sahel Ashhab

Continue reading “March Meeting Quantum Computing Schedule”

Posthumous ArXiv Posting

Hm, today we seem to have a posting from beyond the grave, arXiv:1003.2133:

Proof of the Ergodic Theorem and the H-Theorem in Quantum Mechanics
Authors: John von Neumann
Abstract: It is shown how to resolve the apparent contradiction between the macroscopic approach of phase space and the validity of the uncertainty relations. The main notions of statistical mechanics are re-interpreted in a quantum-mechanical way, the ergodic theorem and the H-theorem are formulated and proven (without “assumptions of disorder”), followed by a discussion of the physical meaning of the mathematical conditions characterizing their domain of validity.

Quantum Bacon

And here I thought I was the king (err Pontiff) of quantum Bacon, but no: follow @kenfagerdotcom on twitter who describes himself as “Inventor of Quantum Bacon and accomplished lover.”

Quantum Cartoons

Richard, a long while back (yes, I’m cleaning my inbox!), sent me some cartoons that were apparently floating around in the 70s when he did his BS in Chemistry that are quite amusing:

Quantum LSD

Oh man sometimes even I, a staunch Caltech grad, wish I could be at MIT. The MIT QIP seminar this next Monday looks…intriguing (Monday 10/26 at 4:00 in 36-428 silly MITers and their numbered buildings, so cold.):

David Kaiser (MIT)
How the Hippies Saved Physics
Abstract:
In recent years, the field of quantum information science-an amalgam of topics ranging from quantum encryption, to quantum computing, quantum teleportation, and more-has catapulted to the cutting edge of physics, sporting a multi-billion-dollar research program, tens of thousands of published research articles, and a variety of device prototypes. This tremendous excitement marks the tail end of a long-simmering Cinderella story. Long before the big budgets and dedicated teams, the field smoldered on the scientific sidelines. In fact, the field’s recent breakthroughs derive, in part, from the hazy, bong-filled excesses of the 1970s New Age movement. Many of the ideas that now occupy the core of quantum information science once found their home amid an anything-goes counterculture frenzy, a mishmash of spoon-bending psychics, Eastern mysticism, LSD trips, CIA spooks chasing mind-reading dreams, and comparable “Age of Aquarius” enthusiasms. For the better part of two decades, the concepts that would,in time, blossom into developments like quantum encryption were bandied about in late-night bull sessions and hawked by proponents of a burgeoning self-help movement-more snake oil than stock option. This talk describes the field’s bumpy transition from New Age to cutting edge.

I knew that the hippies drove the computer revolution but did not know that they are also responsible for quantum information science šŸ™‚

Bayesians Say the Cutest Things

The Dutch book argument of Bruno de Finetti is an argument which is supposed to justify subjective probabilities. What one does in this argument is gives probabilities an operational definition in terms of the amount one is willing to bet on some event. Thus a probability p is mapped to your being willing to make a bet on the event at 1-p to p odds. In the Dutch book argument one shows that if one takes this operational meaning and in addition allows for the person you are betting to take both sides of the bet, then if you do not follow the axiomatic laws of probability, then the person betting against you can construct a Dutch book: a set of bets in which the person you are betting against always wins. For the best explanation and derivation of this result that I know, consult the notes written by Carl Caves: Probabilities as betting odds and the Dutch book.
Now I have many issues with the Dutch book argument, the first and foremost being that it is a ridiculous setup. I mean how often do you place a bet in which you are willing to give both sides of the bet (buy and sell)? “Yes, I would like to either buy or sell a lottery ticket please?” Sure you can do it, but there are many reasons why money has a value outside of the single bet being placed, and therefore buying (giving someone your money and getting paid back if you win the bet) versus selling (recieving money and then having to pay off the bet if you lose) are not symmetric in any world where the unit being exchanged has a temporal value and the bet is placed before the event is resolved. I am, indeed, a one-sided Bayesian. I will leave it up to the reader to construct the axioms of probability by which I work.
Amusingly, at least to me, this objection does not seem to be raised much in the literature on the Dutch book argument. But the other day I found a great quote relevant to this objection which I just have to share. This is from Artificial Intelligence: A Modern Approach by Russell and Norvig. In this book they discuss but don’t prove the de Finetti’s argument. Then they say

One might think that this betting game is rather contrived. For example, what if one refuses to bet? Does that end the argument? The answer is that the betting game is an abstract model for decision-making situation in which every agent is unavoidably involved at every moment. Every action (including inaction) is a kind of bet, and every outcome can be seen as a payoff of the bet. Refusing to bet is like refusing to allow time to pass.

You heard it here first people: if you want to stop time all you have to do is not bet! Crap I have homework due tomorrow what should I do? Well certainly you should not bet, because we all know that refusing to bet is refusing to allow time to pass. ROFL Baysians are so cute when they try to justify themselves.

Chairs

Two notes on chairs. Michael Green is the new Lucasian chair of Mathematics replacing the esteemed Stephen Hawking. Green helped sparked the great optimism in string theory by discovering with John Schwarz the Green-Schwarz anomaly cancellation mechanism.
Elsewhere, the Perimeter Institute has named ten new distinguished research chairs, among them a host of the quantum computing afflicted:

Dorit Aharonov is a Professor in the Department of Computer Science and Engineering at Hebrew University in Jerusalem. She has made major contributions to the theoretical foundations of quantum computation, in particular in the context of understanding and counteracting the effects of ‘noisy’ environments on delicate quantum systems performing computations, the identification of a quantum to classical phase transition in fault tolerant quantum computers, the development of new tools and approaches for the design of quantum algorithms, and the study of ground states of many body quantum Hamiltonians for various classes of Hamiltonians, from a computational complexity point of view. In 2006 she was awarded the Krill prize for excellence in scientific research. Dr. Aharonov is on the faculty of Perimeter Scholars International.
Patrick Hayden holds the Canada Research Chair in the Physics of Information at McGill University. His research focuses on finding efficient methods for performing the communication tasks that will be required for large-scale quantum information processing. This includes the development of methods for reliably sending quantum states through ‘noisy’ media and for protecting quantum information from unauthorized manipulation. He has also applied these techniques to the question of information loss from black holes. Among Dr. Hayden’s honors, he is a past Alfred P. Sloan Foundation Fellow and Rhodes Scholar.
Christopher Isham is a Senior Research Investigator and Emeritus Professor of Theoretical Physics at Imperial College London. He is a former Senior Dean of the College. Dr Isham has made many important contributions in the fields of quantum gravity and the foundations of quantum mechanics. Motivated by the ‘problem of time’ in quantum gravity, he developed a new approach to quantum theory known as the ‘HPO formalism’ that enables the theory to be extended to situations where there is no normal notion of time (such as in Einstein’s theory of general relativity). Since the late 1990s, Dr. Isham has been developing a completely new approach to formulating theories of physics based on the mathematical concept of a ‘topos’. This gives a radically new way of understanding the traditional problems of quantum theory as well as providing a framework in which to develop new theories that would not have been conceived using standard mathematics. From 2001-2005, Dr. Isham was a member of Perimeter Institute’s Scientific Advisory Committee; during the last year he was the Chair of the Committee.
Leo Kadanoff is a theoretical physicist and applied mathematician based at the James Franck Institute at the University of Chicago. He is considered a pioneer of complexity theory, and has made important contributions to research in the properties of matter, the development of urban areas, statistical models of physical systems, and the development of chaos in simple mechanical and fluid systems. His is best known for the development of the concepts of “scale invariance” and “universality” as they are applied to phase transitions. More recently, he has been involved in the understanding of singularities in fluid flow. Among Dr. Kadanoff’s many honours, he is a past recipient of the National Medal of Science (US), the Grande Medaille d’Or of the AcadāˆšĀ©mie des Sciences de l’Institut de France, the Wolf Foundation Prize, the Boltzmann Medal of the International Union of Pure and Applied Physics, and the Centennial Medal of Harvard University. He is also a past President of the American Physical Society. Dr. Kadanoff is on the faculty of Perimeter Scholars International.
Renate Loll is a Professor of Theoretical Physics and a member of the Institute for Theoretical Physics in the Faculty of Physics and Astronomy at Utrecht University. Her research centers on quantum gravity, the search for a consistent theory that describes the microscopic constituents of spacetime geometry and the quantum-dynamical laws governing their interaction. She has made major contributions to loop quantum gravity, and with her collaborators, has proposed a novel theory of Quantum Gravity via ‘Causal Dynamical Triangulations.’ Dr. Loll heads one of the largest research groups on nonperturbative quantum gravity worldwide, and is the recipient of a prestigious personal VICI-grant of the Netherlands Organization for Scientific Research. She is also a faculty member of Perimeter Scholars International.
Malcolm Perry is a Professor of Theoretical Physics in the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge and a Fellow of Trinity College, Cambridge. His research centers upon general relativity, supergravity and string theory. Dr. Perry has made major contributions to string theory, Euclidean quantum gravity, and our understanding of black hole radiation. With Perimeter Institute Faculty member Robert Myers, he developed the Myers-Perry metric, which shows how to construct black holes in the higher spacetime dimensions associated with string theory. Dr. Perry’s honours include an Sc. D. from the University of Cambridge. Dr. Perry is also on the faculty of Perimeter Scholars International.
Sandu Popescu is a Professor of Physics at the H. H. Wills Physics Laboratory at the University of Bristol, and a member of the Bristol Quantum Information and Computation Group. He has made numerous contributions to quantum theory, ranging from the very fundamental, to the design of practical experiments (such as the first teleportation experiment), to patentable commercial applications. His investigations into the nature of quantum behavior, with particular focus on quantum non-locality, led him to discover some of the central concepts in the emerging area of quantum information and computation. He is a past recipient of the Adams Prize (Cambridge), and the Clifford Patterson Prize of the Royal Society (UK).
William Unruh is a Professor of Physics at the University of British Columbia who has made seminal contributions to our understanding of gravity, black holes, cosmology, quantum fields in curved spaces, and the foundations of quantum mechanics, including the discovery of the Unruh effect. His investigations into the effects of quantum mechanics of the earliest stages of the universe have yielded many insights, including the effects of quantum mechanics on computation. Dr. Unruh was the first Director of the Cosmology and Gravity Program at the Canadian Institute for Advanced Research (1985-1996). His many awards include the Rutherford Medal of the Royal Society of Canada (1982), the Herzberg Medal of the Canadian Association of Physicists (1983), the Steacie Prize from the National Research Council (1984), the Canadian Association of Physicists Medal of Achievement (1995), and the Canada Council Killam Prize. He is an elected Fellow of the Royal Society of Canada, a Fellow of the American Physical Society, and a Fellow of the Royal Society of London, and a Foreign Honorary Member of the American Academy of Arts and Science.
Guifre Vidal is a Professor in the School of Physical Sciences at the University of Queensland, who has made important contributions to the development of quantum information science, with applications to condensed matter theory. His research explores the phenomenon of entanglement, the renormalization group, and the development of tensor network algorithms to simulate quantum systems. Dr. Vidal’s past honors include a Marie Curie Fellowship, awarded by the European Union, and a Sherman Fairchild Foundation Fellowship. He is a Federation Fellow of the Australian Research Council.
Mark Wise is the John A. McCone Professor of High Energy Physics at the California Institute of Technology. He has conducted research in elementary particle physics and cosmology, and shared the 2001 Sakurai Prize for Theoretical Particle Physics for the development of the ‘Heavy Quark Effective Theory’ (HQET), a mathematical formalism that enables physicists to make predictions about otherwise intractable problems in the theory of the strong interactions of quarks. He has also published work on mathematical models for finance and risk assessment. Dr. Wise is a past Sloan Foundation fellow, a fellow of the American Physical Society, and a member of the American Academy of Arts and Sciences and of the National Academy of Sciences.

Apps to Randomize Your World (Some Using Quantum Physics!)

Update 10/13/09: corrected for ice cream flavor and location, thus merging two related universes.
There is a story about Richard Feynman that while he was at Princeton MIT he had a hard time with dessert. Apparently they always served either chocolate or vanilla ice cream and Feynman would agonize over which he wanted that night. Then one day he decided that he was wasting his time making this decision and so he would solve this by only choosing vanilla chocolate and from that point on in life that is what he did. He no longer wasted time choosing, and, apparently, ate a lot of vanilla chocolate ice cream. Of course there is an equally valid and equally elegant solution to this problem which is in fact the exact opposite of Feynman’s deterministic solution: choose randomly! Chocolate or vanilla? Choose randomly. Stop at the stop sign or not? Choose randomly (okay maybe not!) Of course there is the question of exactly how you choose randomly. For some, dice may suffice, but isn’t there a better way than carrying around a bag of dice which makes you look like your heading out for a night of RPGing?
Well today I’m happy to report to you that there is a solution to this problem: use your iPhone! As many of you know, when I’m stuck on a plane I like to write iPhone apps (thus leading to my app for accesing the arXiv: arXiview.) So on a few of these flights recently I kludged together a new iPhone app: MakeRandom. This app gives you access to custom random lists, dice, random numbers, and random words. To get the randomness you just set up the list you want to randomly select from and shake! Exciting, no? But today I got an email about an even more exciting use of randomness in the iPhone: Universe SplitterĀ¬Ā©:

Scientists say that every quantum event plays out simultaneously in every possible way, with each possibility becoming real in a separate universe. You can now harness this powerful and mysterious effect right from your iPhone or iPod Touch!
How? Whenever you’re faced with a choice — for example, whether to accept a job offer or to turn it down — just type both of these actions into Universe SplitterĀ¬Ā©, and press the button.
Universe SplitterĀ¬Ā© will immediately contact a laboratory in Geneva, Switzerland, and connect to a Quantis brand quantum device, which releases single photons into a partially-silvered mirror. Each photon will simultaneously bounce off the mirror and pass through it — but in separate universes.
Within seconds, Universe SplitterĀ¬Ā© will receive the experiment’s result and tell you which of the two universes you’re in, and therefore which action to take. Think of it — two entire universes, complete with every last planet and galaxy, and in one, a version of you who took the new job, and in the other, a version of you who didn’t!

Classic! Watch as this quantum physicist who wrote an app for randomness slaps himself on the forehead for not thinking of this. Check out Universe Splitter’s website for a great quote by Garrett Lisi.
Universe SplitterĀ¬Ā© is available from the iTunes store for $1.99 here
MakeRandom is also available from the iTunes store for $0.99here.
Below the fold: screenshots and a philosophical discussion of the difference between the applications.
Continue reading “Apps to Randomize Your World (Some Using Quantum Physics!)”

Does Quantum Uncertainy Come From the Foundations of Math?

Over at Asymptotia, Len Adleman (the A in RSA, founder of DNA computation (but not the A in DNA!), and a discoverer of the APR primality testing algorithm) has a guest post about the foundations of quantum theory. Len suggests, if I understand him correctly, that one should attempt to understand the uncertainty arising in quantum theory as being of the same nature as the fact that there exists statements which cannot be proven true or false within a fixed set of powerful enough axioms.
First of all, I know I’ve heard a similar argument before, but can’t seem to find the reference! Any foundations (or other) people want to supply those as I’m sure they would be welcomed in the comment section of Asymptotia. Second, I find it interesting that Len seems most troubled by the uncertainty arising in quantum theory and not by, for example, Bell inequalities. I’m no so sure many of us are troubled by this aspect (that it is probabilistic and not deterministic) of quantum theory, in and of itself. That is to say if the world had a probabilistic local hidden variable theory, would we be arguing about the foundations of quantum theory? Third, this of course brings to mind the Kochen-Specker theorem which shows that there is no non-contextual hidden variable theory of quantum mechanics. Indeed contextuality reminds one a lot of a “choice of axiomatic system.” It would indeed be neat if one could make this into a more established result. But in particular one would need to argue why Hilbert space best captures the idea of a set of axioms. Finally, because I think Bell inequalities are essential for understanding what makes quantum theory truely unique (yes I’m biased), I’m curious as to whether mathematicians have ever considered the notion of “local axioms”, i.e. axioms which live in spacetime?