Quantum Computing

Since I sort of implied a series in the previous post, and I have no better ideas, here's a look at Thursday's DAMOP program: Thursday Morning, 8am (yes, they start having talks at 8am. It's a great trial.) Session J1 Novel Probes of Ultracold Atom Gases Chair: David Weiss, Pennsylvania State University Room: Imperial East Invited Speakers:  Cheng Chin,  Markus Greiner,  Kaden Hazzard,  Tin-Lun Ho  Session J2 Coherent Control with Optical Frequency Combs Chair: Linda Young, Argonne National Laboratory Room: Imperial Center Invited Speakers:  J. Ye,  Moshe Shapiro,  W. Campbell,  …
The conference I'm at this week is the annual meeting of the Division of Atomic, Molecular, and Optical Physics of the American Physical Society (which this year is joint with the Canadian version, the Division of Atomic and Molecular Physics and Photon Interactions, or "DAMPΦ." The Greek letter is a recent addition-- as recently as 2001, they were just DAMP.). As the name suggests, this is a meeting covering a wide range of topics, and in some ways is like two or three meetings running in parallel in the same space. You can see the different threads very clearly if you look at the different…
What's the application? An optical frequency comb is a short-duration pulsed laser whose output can be viewed as a regularly spaced series of different frequencies. If the pulses are short enough, this can span the entire visible spectrum, giving a "comb" of colored lines on a traditional spectrometer. This can be used for a wide variety of applications, from precision time standards to molecular spectroscopy to astronomy. What problem(s) is it the solution to? 1) "How do I compare this optical frequency standard to a microwave frequency standard?" 2) "How do I calibrate my spectrometer well…
Several people have sent me links to news stories about last week's Nature paper, "Quantum ground state and single-phonon control of a mechanical resonator." (It was also presented at the March Meeting, but I didn't go to that session). This is billed as the first observation of quantum phenomena with a "macroscopic" or "naked eye visible" object. Of course, there's a nice bit of irony in a story about quantum effects in a "naked eye visible" object that is accompanied by an image of the object in question taken with a scanning electron microscope. The longest dimension of the object in…
The twelfth annual SqUINt conference is being held this week and unfortunately I'm missing my favorite conference (though a gaggle of grad students have been sent Santa Fe bound.) The schedule looks really good this year including a great list of invited speakers (Scott Aaronson (MIT), Rainer Blatt (Innsbruck), Matt Hastings (Station Q), Dieter Meschede (Bonn), Keith Schwab (Caltech), and John Watrous (Waterloo)). Notice the awesome mix of theory and experiment...good stuff. Hope everyone who is attending is having a fantastic time: have some green chiles for me please.
Derek Lowe has a post talking about things biologists should know about medicinal chemistry. It's a good idea for a post topic, so I'm going to steal it. Not to talk about medicinal chemistry, or biologists, of course, but to talk about my own field, and what everyone-- not just scientists-- should know about quantum physics. Not just humans, either-- even dogs should know this stuff. 1) Quantum physics is real. Probably the hardest quantum idea to accept is the notion of vacuum energy and "virtual particles"-- stuff appearing out of empty space, then disappearing again seems almost too weird…
Today's Quantum Optics lecture is about quantum computing experiments, and how different types of systems stack up. Quantum computing, as you probably know if you're reading this blog, is based on building a computer whose "bits" can not only take on "0" and "1" states, but arbitrary superpositions of "0" and "1". Such a computer would be able to out-perform any classical computer on certain types of problems, and would open the exciting possibility of a windows installation that is both working and hung up at the same time. There are roughly as many types of proposed quantum computers as…
Buried in the weekend links dump at the arxiv blog was Scalable ion traps for quantum information processing: We report on the design, fabrication, and preliminary testing of a 150 zone array built in a `surface-electrode' geometry microfabricated on a single substrate. We demonstrate transport of atomic ions between legs of a `Y'-type junction and measure the in-situ heating rates for the ions. The trap design demonstrates use of a basic component design library that can be quickly assembled to form structures optimized for a particular experiment. At first glance, this isn't a sexy paper…
Yes, it's a slow dance:Through the hourglass I saw you, in time you slipped away When the mirror crashed I called you, and turned to hear you say If only for today I am adiabatic Take my pulsed gates away arXiv:0905.0901, "Adiabatic Gate Teleportation" by Dave Bacon and Steve Flammia (As seen on arXiview)
As I understand it, the Physics ArXiv Blog is not affiliated with the people who actually run the Arxiv (Paul Ginsparg et al.). Which is probably good, as I'm never entirely sure how seriously to take the papers they highlight. Take yesterday's post, Diamond Challenges for Quantum-Computing Crown, which is about a paper that asks the question Could one make a diamond-based quantum computer?. It's an interesting idea, and something I wrote about last year, so it seems like a promising topic. The preprint in question, though, is a little dodgy. It's indifferently proofread, with all sorts of…
Quantum ghosts, dynamical decoupling, why a diamond is forever in quantum computing, transversal press, quantum phrases I can't grok, and quantum jumping. Quantum ghosts: here and here. These articles describe the work reported in Laing, Rudolph, and O'Brien. "Experimental Quantum Process Discrimination." Phys. Rev. Lett., 102, 160502 (2009) arXiv:0801.3831. The idea is to discriminate "non-orthogonal" quantum processes via the use of entanglement, which is cool. (I'm a bit surprised that this classic paper is not referenced.) Optimized dynamical decoupling performed in ions at NIST. Paper…
Michael Biercuk sends me a note about an upcoming workshop on dynamic decoupling. He's trying to get a gauge of the interest in such a workshop:Upcoming International Workshop on Dynamical Decoupling (IWODD) Expected Date: October, 2009 Location: Boulder, CO By Invitation Only Interested participants please contact Michael J. Biercuk, biercuk at boulder.nist.gov Those interested should shoot Michael an email.
Physics World has a nice news article about a new experimental development in quantum computing, based on a forthcoming paper from the Wineland group at NIST in Boulder. I'd write this up for ResearchBlogging, but it's still just on the arxiv, and I don't think they've started accepting arxiv papers yet. The Physics World piece summarizes the key results nicely: Now, Brad Blakestad and colleagues at the National Institute of Standards and Technology (NIST) in Boulder, Colorado have created a junction in an ion trap in which there is practically no heating. Constructed from laser-machined…
Over 9 months ago I decided to apply for teaching tenure track jobs. Then the economy took what can best be described as a massive, ill-aimed, swan dive. Thus creating an incredible amount of stress in my life. So what does a CS/physics research professor do when he's stress? The answer to that question is available on the iTunes app store today: arXiview. What better way to take out stress and at the same time learn objective C and write an iPhone app that at least one person (yourself) will use? What is arXiview? It is yet another arXiv viewer (there are two others available, last I…
The survey of abused words in quantum computing shows the word "exponential" as having an, um, exponential, lead over its competitors. My own personal choice for the most abused word was "scalable," a word that is, in my opinion, the least debated, but most important, concept in quantum computing today. A word which everyone uses but whose definition is strangely missing from all almost all papers that use the word. Here are some thoughts on this word, what it means to particular groups, and what I, in my own pomposity, think the word really should mean. Note the title of this post is…
Lately I've been giving a lot of thought to a question that I'm nearly constantly asked: "So...[long pause]...are you a physicist...[long pause]...or are you a computer scientist?" Like many theorists in quantum computing, a field perched between the two proud disciplines of physics and computer science (and spilling its largess across an even broader swath of fields), I struggle with answering this question. Only today, after a long and torturous half year (where by torture, I mean interviewing for jobs, not the eerily contemporaneous fall of the world's finances) in which I have been…
Kamil sends along a pointer to www.playqubit.com. "Qubit," according to the website is a new quiz show on the Discovery channel:Qubit is a quiz show for the 21st century - fast-paced, cut-throat and fun! Driven by stunning HD visuals, Qubit showcases science, technology and natural history. Not your ordinary quiz show, Qubit challenges convention by including the odd, unique and truly quirky aspects of the world of science. Sounds like a fun show. But "Qubit"? Really? I wonder if the PR firm that sold them on that name knew what the word meant and whether Ben Schumacher is offended or…
For those local to Seattle, I'm talking tomorrow in the Paul Allen center:TIME: 1:30 -- 2:30 pm, Tuesday, Feb 24, 2009 PLACE: CSE 503 SPEAKER: Dave Bacon, University of Washington TITLE: Symmetry in Quantum Algorithms ABSTRACT: Quantum computers can outperform their classical brethren at a variety of algorithmic tasks. Uncovering exactly when quantum computers can exponentially outperform classical computers is one of the central questions facing the theory of quantum algorithms today. In this talk I will argue that a key piece of this puzzle is the role played by symmetry in quantum…
Quantum computing continues to grow in Canada. Congrats to the IQC at the University of Waterloo who now, truly are the center of the quantum computing universe:With matching funds from the province of Ontario and RIM founder Mike Lazaridis, University of Waterloo's Institute for Quantum Computing will receive $150 million to build a research facility and attract talent Canada will become home to the largest concentration of quantum computing talent in the world, thanks to $150 million in funding from government and the founder of Research In Motion Ltd. The 2009 federal budget plan released…
I'm not sure what the BBVA Foundation is, but they've awarded a Basic Science prize to Ignacio Cirac and Peter Zoller: The Basic Sciences award in this inaugural edition of the BBVA Foundation Frontiers of Knowledge Awards has been shared by physicists Peter Zoller (Austria, 1952) and Ignacio Cirac (Manresa, 1965), "for their fundamental work on quantum information science", in the words of the jury chaired by Theodor W. Hänsch, Nobel Prize in Physics. Zoller and Cirac's research is opening up vital new avenues for the development of quantum computers, immensely more powerful than those we…