I say, We can dance, We can dance, Everything out of control

A psuedo-paper dance today: a perspective I wrote just appeared in Science. The perspective is about this paper: “Symmetrized Characterization of Noisy Quantum Processes,” Joseph Emerson, Marcus Silva, Osama Moussa, Colm Ryan, Martin Laforest, Jonathan Baugh, David G. Cory, and Raymond Laflamme, Science 317, 1893 (2007) Check out my raytracing skillz in the picture accompanying the perspective 🙂

New Scientist May Be New, But About That Science?

Via Science after Sunclipse, I find a comment by Greg Egan on The n-category Cafe where I was led to this letter to New Scientist:

Superluminal siblings
22 September 2007
From New Scientist Print Edition.
Nick Webb, London, UK
Robbie and Fred are twins who live together. Wearing identical suits, they leave their house at the same time heading in opposite directions. One twin carries a hidden green wallet; the other has a red one. The wallets are not visible.
Unfortunately, Robbie is mugged and the redness of his wallet is revealed. In quantum terms he is measured and forced to take a value.
An observer can now deduce that Fred’s wallet is green, and if put to the test this will prove to be the case no matter where or when Fred is interrogated.
There is no need for faster-than-light communication or spooky interaction at distance – just knowledge of the initial conditions. I can’t see anything wrong with this analogy. Am I missing something?
The editor writes:
No, it’s exactly right.

At which point my brain just exploded.

And Thanks For All The Fish

Michael Nielsen’s switchin’ fields. I’m envious but also sad. Envious that he gets to do something totally cool and new, but sad that I won’t be randomly bumping into him at conferences where I try to explain to him some crazy idea I’m working on and then get to hear his wonderful laugh at my silly ideas. Oh yeah, and when am I ever going to get to use this joke again, huh?
On the more serious side of things, I myself often think about what I would do if I wasn’t working in quantum computing. Which always leads me to think about why I’m still in the field in the first place (history ain’t a good reason, in fact I’d say it is the worst reason of all.) There are mostly two or three things that really keep me in the field these days. One is that I really really really want to see a quantum computer built. And I think the current roadmap ain’t got nothing to do with how a large scale quantum computer will be built. I’ve always said that if I could see how some scheme for quantum computing would really work to build a large quantum computer I’d drop my theorists clothes and work towards building the damn thing. And I work today in the field because I’m naive enough to think that I might be able to contribute to the more radical ideas I think are needed for building a quantum computer.
The second thing which keeps me going these days is a personal quirk. When I first started working in quantum computing I was trying to solve NP-complete problems efficiently on a quantum computer. I was young and I was naive, yes. But I was also drawn to the promise of the power of quantum algorithms. And damnit I still want to come up with an algorithm for a quantum computer which is of some importance. Yep, I really really really want to at least break a public key cryptosystem!
Finally I would say that the other thing which keeps me in quantum computing these days is just to see what Scott Aaronson will do next. Actually what I really mean by this is I do think that quantum information science provides an interesting insight into computation and into physics. Quantum computing beyond the hype of a quantum computer. Quantum computing for its own intellectual sake of revealing more about our physical and computational universe. Quantum computing because (to channell Feynman’s ghost) our world is quantum damnit, and all these views of the interaction betwen physics and computer science which just go with classical computing are interesting but fundamentally lacking.
Of course all this thinking about what keeps me in the field of quantum computing or even in academia also is just my way of avoiding answering the question of what I would do if I wasn’t in the field. But that’s easy for me to answer I guess. I’d be at a computer startup (my original goal in life was to work at Apple, you know) or trying to get a job at someplace like D.E. Shaw where my friends who work there tell me exciting stories of interesting problems and silly sums of money which will let them do what they want in a few short years. Or maybe I’d be a lift operator at a ski resort 🙂

Professorship of Quantum Physics

Here is an awesome position for one of you bigwigs out there:

The Board of Electors to the Professorship of Quantum Physics, to be held in the Department of Applied Mathematics and Theoretical Physics (DAMTP), invite applications for this Professorship, to take up appointment on 1 January 2008 or as soon as possible thereafter. Applications are welcome from persons working in the broad areas of quantum computation and quantum information theory (with these taken to include quantum cryptography and quantum communication theory). The Professor will have an outstanding international reputation in their field of research and will be expected to provide strong academic leadership in research, teaching and other activities of DAMTP.
The Chair has become vacant on the departure of the post holder, Professor Artur
Ekert, who played a leading role in establishing a successful Centre for Quantum
Computation in DAMTP housing an internationally leading research activity in quantum information science. The Department wishes to appoint a new Professor who is able to sustain this general line of research to the highest possible standards.
Further information may be obtained from the Academic Secretary, University Offices, The Old Schools, Cambridge, CB2 1TT, (email: ibise@[elephant]admin.cam.ac.uk remove the [elephant] to get the valid email), to whom a letter of application should be sent, together with details of current and future research plans, a curriculum vitae, a publications list and form PD18 with details of two referees, so as to reach him no later than 30 September 2007.
Informal enquiries about this Professorship may be directed at any time to Professor Peter Haynes, Head of the Department of Applied Mathematics and Theoretical Physics, telephone: (01223) 337862 or email: p.h.haynes@[elephant]damtp.cam.ac.uk, remove the [elephant] to get the valid email. Further information about the post and the Department may be found at http://www.damtp.cam.ac.uk/.

Oh, and to translate this post across the pond, “centre”=”center” and “1 January 2008” is “January 1, 2008.”

Parallel Universes

I know they exist because slashdot and The New Scientist and some other Site tell me they exist. I keep wondering how I can find my way to a parallel universe where I don’t spend my time reading those articles, but can’t quite get the Hadamard matrix to enact the proper interference pattern.

Is the Sky Falling? Fundanationalist Edition

I’m as much a nationalist as Dick Cheney is a peace loving hippie. Except, of course, when it comes to funding. Yes, I am a “fundanationalist.” Particularly funding of quantum computing. Selfish? Indeed! And you would be too if your salary came from agencies scooped straight out of a bowl of alphabet soup.
So I have no qualms asking the question “Is the US the leading place to do quantum computing theory research?” Now how might one check this out? One way would be to look at the data from the last two QIP conferences. QIP is certainly the top conference for a certain kind of quantum computing theory, one which is more computer sciency than physicy. Note that over the last two QIPs there has been a more democratic method for inviting speakers, so that this data is arguably fairly representative of the work the community currently values. Here are numbers:

QIP 2007 [Brisbane, Australia]
US 12
Canada 8
Europe 13
Asia 1
Australia 1
Israel 2
QIP 2006 [Paris, France]
US 11
Canada 8
Europe 16
Asia 2
Australia 1
Israel 2

Note that I took the authors current affiliation and not the affiliation when they spoke, as I’m more interested in what the current state of theory research is. Well so the United States has less that one third of the speakers. So I would say that the US is certainly not dominating quantum computing research, but is in a three way tie for the top spot with Europe and Canada. Considering the lack of hiring of top quantum computing people in US universities (certain exceptions, of course, apply) I would guess that this divide is only going to deepen.
Of course truthfully I am happy to see quantum computing funded everywhere. However I wonder if this view is shared by those deep in the heart of government funding agencies. Is third place good enough for quantum computing theory research in the United States?

Quantum Computing Without Working in a Quantum Garage?

Over at Computational Complexity, Bill Gasarch asks about some of the things he’s heard about quantum computing:

I have been told quite often that
“You don’t have to understand Quantum Mechanics to work in Quantum Computing.”
Thats a good thing since I’ve also been told
“Nobody really understands Quantum Mechanics.”
I’ve also been told
“You don’t have to have studied Quantum Mechanics to work in Quantum Computing.”
I am skeptical of that.

Which reminds me of story about how I first tried to learn quantum theory. When I was growing up we belonged to a science book club. Most of the books we ordered where the fairly standard popular science kind of books. But there were more technical books available and I had already read a lot of popular science on quantum theory, so I decided that I wanted to get a real textbook on quantum theory.
So I ordered up this textbook and dived right in. Now the first thing this book talks about is the ultraviolet catastrophe and Planck’s solution to this problem (of course this is a made up history: Planck wasn’t trying to solve the ultraviolate catastrophe when he derived his theory of quanta.) And in this problem one of the essential points was that if you took this equation that had a symbol like [tex]$$int $$[/tex] and turned it into a symbol like [tex]$$Sigma$$[/tex], then you could avoid this catastrophe. Now I knew what the latter meant, a sum, but I had no clue what that first symbol was. But I did know a chemistry teacher who had gone to Berkeley, so I thought he would know. So I went and showed him the book, and he said “Oh! That’s an integral symbol.” And then he told me that I would have to learn Calculus to understand what this meant. Really! You have to understand calculus to learn quantum theory. Well that was a setback. (Luckily our local library had a calculus book, which I promptly checked out and learned calculus from. Ah, those were the days. BTW, a math teacher I had in high school claimed he could teach his eight year old calculus.)
Okay, so now you’re saying, “Get to the point Dave!” And certainly most of you might guess that the point I’m trying to make is that you don’t need calculus to learn quantum computing (true) or that you don’t need to know quantum physics to learn quantum computing (note I said “physics” here.). Of course the later is true, you could pick up Nielsen and Chuang and learn quantum computing without ever solving a particle in a box problem in quantum physics. But why would you want to do this? When you really care about learning something, it’s not about what you do or don’t need to begin learning, it’s about trying to grab ahold of as much information and having as much fun as possible. For example, you could turn this question around and ask, “Do you need to have taken a course in computational complexity in order to do quantum computing?” The answer is, I think (no wait, I know from personal experience!), “no.” But why would you not want to learn about P, NP, PP, BPP, EXP, etc. (and the new complexity class MIT. By the way MIT is contained inside of CIT. I have a proof of this, but it doesn’t fit in the margins of this blog.)? So while I think it is certainly true that you could learn quantum computing without taking a course (or learning on your own) in quantum physics, why in the world would you want to do this? Why not learn as much as you can about both “quantum” and about “computing”? This doesn’t guarantee success or anything, but I can guarantee you that it would benefit your soul (and it might even lead to things like physicists designing algorithms where scattering off a tree solves the NAND tree problem.)
(The main point of Bill’s article, of course is to ask whether quantum physicists should learn quantum computing, to which I refer the reader to Scott Aaronson’s answer in the comment section of the post.)

QIP 2008 in New Delhi

A slightly panicked email correspondent notes that QIP 2008’s deadline is fast approaching: September 20. QIP’s webpage is here, allthough it seems to be really slow to load, so you might try google’s cache version here.
I had heard that the next QIP would be in China, but recently heard a rumor that it would be
in Albuquerque (mmm, green chiles.)
Update: Cris Moore (no “h”, peoples!) writes to say that QIP 2009 will indeed be in New Mexico (mmm, sopaipillas.)

Postdocs, Postdocs

Ann of Caltech sends me some postdoc positions at the institute of technology:

CENTER FOR THE PHYSICS OF INFORMATION
CALIFORNIA INSTITUTE OF TECHNOLOGY
Postdoctoral Research Positions
The Center for the Physics of Information at the California Institute of Technology will have postdoctoral scholar positions available beginning in September 2008. Researchers interested in all aspects of the interface between information science and physical science are invited
to apply.
Please apply on-line at http://www.ist.caltech.edu/joinus/positions.html#postdoc. Electronic copies of your curriculum vitae, publication list, statement of research interests, and three letters of recommendation are required.
The deadline for receipt of all application materials is December 17, 2007.
The California Institute of Technology is an Equal Opportunity/Affirmative Action employer. Women, minorities, veterans and disabled persons are encouraged to apply.
INSTITUTE FOR QUANTUM INFORMATION
CALIFORNIA INSTITUTE OF TECHNOLOGY
Postdoctoral Research Positions
The Institute for Quantum Information at the California Institute of Technology will have postdoctoral scholar positions available beginning in September 2008. Researchers interested in all aspects of quantum information science are invited to apply.
Please apply on-line at www.iqi.caltech.edu. Electronic copies of your curriculum vitae, publication list, statement of research interests, and three letters of recommendation are required. The deadline for receipt of all application materials is December 17, 2007.
The California Institute of Technology is an Equal Opportunity/Affirmative Action employer. Women, Minorities, Veterans and Disabled Persons are encouraged to apply.

I’m happy to see the CEPI ad since we really need to counter the number of quantum computing “centre”s out there with the wrong spelling of the word “center”.