Quantum Computing

A few years back, I became aware of Mike Brotherton's Launch Pad Astronomy Workshop, and said "somebody should do this for quantum physics." At the time, I wasn't in a position to do that, but in the interim, the APS Outreach program launched the Public Outreach and Informing the Public Grant program, providing smallish grants for new public outreach efforts. So, because I apparently don't have enough on my plate as it is, I floated the idea with Steve Rolston at Maryland (my immediate supervisor when I was a grad student), who liked it, and we put together a proposal with their Director of…
In odd-numbered years (by the Gregorian calendar, anyway), the University of Toronto offers the John Stewart Bell Prize for Research on Fundamental Issues in Quantum Mechanics and Their Applications. This is not connected to the Jon Stewart of the Daily Show-- he's purely classical, as you can tell from the fact that there's no "h" in his name. It honors the great Irish physicist John Bell, whose theorem showing that quantum models could be experimentally distinguished from local hidden variable theories helped kick off the thriving field of quantum information. (Bell's contribution is a big…
The second day of the "Quantum Boot Camp" was much lighter on talks. The only speaker was Ray Laflamme from the Institute for Quantum Computing in Waterloo, who gave a nice introduction to quantum technologies. While he did spend a bit of time at the start going through Shor's algorithm for factoring numbers (following up a discussion from Wednesday), he mostly focused on ways to use quantum physics to improve sensors of technological interest. So, for example, he talked about how efforts to develop techniques for error-correcting codes in liquid state NMR quantum computing led to the…
Since this part of the trip is actually work-like, I might as well dust off the blog and post some actual physics content. Not coincidentally, this also provides a way to put off fretting about my talk tomorrow... I'm at the Nordita Workshop for Science Writers on quantum theory, which a couple of the attending writers have referred to online as boot camp, though in an affectionate way. The idea is to provide a short crash course on cool quantum physics, so as to give writers a bit more background in subjects they might need to cover. The first talk was from Rainer Kaltenbaek (whose name I…
There's been a bunch of talk recently about a poll on quantum interpretations that showed physicists badly divided between the various interpretations-- Copenhagen, Many-Worlds, etc.-- a result which isn't actually very surprising. Sean Carroll declares that the summary plot is "The Most Embarrassing Graph in Modern Physics, which I think is a bit of an overreaction, but not too much of one. I do strongly disagree with one thing he says in explaining this, though: Not that we should be spending as much money trying to pinpoint a correct understanding of quantum mechanics as we do looking for…
In which I steal an analogy from Joe Emerson to explain the limits of quantum computing. ------------ As previously noted, a couple of weeks ago I went to Canada for the opening of the University of Waterloo's new Quantum Nano Center (their photo gallery includes one picture of me being interviewed, along with lots of more interesting pictures from the day). One of my events there was a panel discussion about the new center and what it will mean, which included me, Raymond Laflamme, the director of the Institute for Quantum Computing, and Mike Lazaridis, the founder of Research in Motion, who…
In which we do a little imaginary Q&A to explain the significance of Tuesday's Nobel Prize to Dave Wineland and Serge Haroche. ------------ I did a quick post Tuesday morning noting that the latest Nobel Prize in Physics was awarded to two big names from my corner of the field. This would've been a great time to drop a long explainer post about what they did and why it's cool, but alas, I have a day job, and the Nobel committee stubbornly refuses to tell me who they're giving the prizes to in advance. Oh, well. Still, I'm just vain enough to think I can add something a little different…
The 2012 Nobel Prize in Physics was announced this morning, going to Serge Haroche and Dave Wineland, "for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems". This isn't a pair that was getting much love from the prognosticators, but they're an excellent choice. And, in fact, commenter KSC correctly picked Wineland in the betting pool and narrowly missed also getting Haroche. Wineland has been on my mental list of people who ought to get a Nobel for a while, especially because he easily could've had a piece of the 1997 prize for laser…
The Links Dump item about software patents this morning includes a lament that there are so many silly little software patents, organized so badly, that finding one you might be infringing would take forever. This may or may not be a convincing argument against them, but for a physics geek like me, my first reaction was "You just need a quantum computer running Grover's algorithm for searching an unsorted database." And I suppose there's a background element for a satirical SF novel in that-- quantum computers ultimately being developed not by banks or the NSA, but by lawyers looking to speed…
It's been a while since I did any ResearchBlogging, first because I was trying to get some papers of my own written, and then because I was frantically preparing for my classes this term (which start Wednesday). I've piled up a number of articles worth writing up in that time, including two papers from an early-August issue of Nature, on advances in experimental quantum computation (the first is available as a free pdf because it was done at NIST, and thus is not copyrightable). These were also written up in Physics World, but they're worth digging into in more detail, in the usual Q&A…
Third of the five research categories within DAMOP that I talked about is Quantum Phenomena. This is a little bit of a catch-all, as there are a few different things going on in this area. They are all unified, though, by the fact that they end up making quantum mechanical effects manifest in some way, either as a means to an end, or just for the sake of showing that quantum mechanics is really weird. What do I mean "making quantum mechanical effects manifest?" Basically, demonstrating one of the essential elements that I talked about last year: showing the wave nature of matter,…
The first of the five categories of active research at DAMOP that I described in yesterday's post is "Ultracold Matter." The starting point for this category of research is laser cooling to get a gas of atoms down to microkelvin temperatures (that is, a few millionths of a degree above absolute zero. Evaporative cooling can then be used to bring the atoms down to nanokelvin temperatures, reaching the regime of "quantum degeneracy." This is, very roughly speaking, the point where the quantum wavelength of the atoms becomes comparable to the spacing between atoms in the gas, at which point the…
That's the title of my slightly insane talk at the DAMOP (Division of Atomic, Molecular, and Optical Physics of the American Physical Society) conference a couple of weeks ago, summarizing current topics of interest in Atomic, Molecular, and Optical Physics. I'll re-embed the slides at the end of this post, for anyone who missed my earlier discussion. I put a ton of work into that talk, and had a huge amount of material that I didn't have time to include. I'd hate for that to go to waste, so I'm going to repurpose it for blog content over the next week or so. It'll probably be about a half-…
One of the odd things about going to conferences is the unpredictable difference between talks and papers. Sometimes, when you go to a talk, you just get an exact repetition of what's in the paper; other times, you get a new angle on it, or some different visual representations that make something that previously seemed dry and abstract really click. And, of course, sometimes you get new hot-off-the-apparatus results that haven't made it into print yet. Maddeningly, there doesn't seem to be any way to know in advance which of these things you're going to get from the title and abstract. It…
That's the title of my talk this morning at DAMOP, where I attempt the slightly insane feat of summarizing a meeting with over 1000 presentations in a single 30-minute talk. This will necessarily involve talking a little bit like the person reading the legal notices at the end of a car commercial, and a few of the guide-to-the-meeting slides will have to flash by pretty quickly. Thus, for the benefit of those who have smartphones and care about my categorization of talks, I have put the slides on SlideShare in advance, and will embed them here: What's So Interesting About AMO Phyiscs?…
I've got three months to decide. I'll be giving an invited talk at the Division of Atomic, Molecular, and Optical Physics (DAMOP) with this title, with a goal of introducing the field to students and physicists from other fields: In recent years, DAMOP has expanded to the point where the meeting can be quite daunting for a first-time attendee. This talk will provide an introduction to some of the most exciting current areas of research in Atomic, Molecular, and Optical physics, intended to help undergraduates, beginning graduate students, or physicists from other fields attending their first…
I hadn't heard anything about Dance of the Photons: From Einstein to Quantum Teleportation before it turned up in my mailbox, courtesy of some kind publicist at Farrar, Straus, and Giroux, otherwise I would've been eagerly anticipating it. Anton Zeilinger is a name to conjure with in quantum optics, having built an impressive career out of doing laboratory demonstrations of weird quantum phenomena. He shared the Wolf Prize earlier this year with John Clauser and Alain Aspect, and the three of them are in a small set of people who probably ought to get a Nobel at some point in the near future…
Last week, John Baez posted a report on a seminar by Dzimitry Matsukevich on ion trap quantum information issues. In the middle of this, he writes: Once our molecular ions are cold, how can we get them into specific desired states? Use a mode locked pulsed laser to drive stimulated Raman transitions. Huh? As far as I can tell, this means "blast our molecular ion with an extremely brief pulse of light: it can then absorb a photon and emit a photon of a different energy, while itself jumping to a state of higher or lower energy." I saw this, and said "Hey, that's a good topic for a blog post…
I'm a big fan of review articles. For those not in academic science, "review article" means a long (tens of pages) paper collecting together the important results of some field of science, and presenting an overview of the whole thing. These vary somewhat in just how specific they are-- some deal with both experiment and theory, others just theoretical approaches-- and some are more readable than others, but typically, they're written in a way that somebody from outside the field can understand. These are a great boon to lazy authors, or authors facing tight page limits ("Ref. [1] and…
Over at Jeff Vandemeer's blog, Rachel Swirsky has a series ofm guest posts (start here if you prefer direct post links) about the recently completed Launch Pad workshop. this is a NASA funded workshop bringing a group of writers together for six days of lectures on modern astronomy from working astronomers. From the workshop web site: Launch Pad is a NASA-funded education/public outreach effort supplementing Mike Brotherton's space-based astronomical research. Our budget allows us to provide a workshop that is essentially free to participants. Our primary goal is to teach writers of all…