Anthropic Challenge

Andrew Jaffe has posted his review of The Goldilocks Enigma: Why is the Universe Just Right for Life? by Paul Davies. Which is an entertaining read, and got me to thinking (okay, what follows doesn’t exactly qualify as thinking, BTW) So some physicists want to use anthropic principles as a solution to the problem of explaining the physics of our universe. But why stop at explaining things like the value of the cosmological constant? Why not go for something bigger, like the question quantum foundations people love: “why quantum theory?” So a challenge: derive quantum theory from the anthropic principle. Do that and I might even begin to believe that the anthropic principle actually has some value beyond making me shout out in pain when reading anthropic arguments 🙂

Postdocs Obey a Perimeter Law?

Postdocs, postdocs, everywhere and not a faculty job to seek (just kidding….or am I 😉 )

Institute for Quantum Computing, University of Waterloo
Applications are invited for postdoctoral positions in any area of quantum information. The starting date of the appointment is open.
A Ph.D. and proven ability, or the potential, for excellent research is required. Successful candidates will be joining a substantial research and training centre in quantum information at Institute for Quantum Computing (IQC). Information about IQC personnel and activities can be found at www.iqc.ca. The IQC is based at the University of Waterloo, and includes, at present, more than a dozen researchers from the Faculties of Engineering, Mathematics and Science. The candidates will also have the opportunity to interact with scientists at the nearby Perimeter Institute for Theoretical Physics, and UW’s Centre for Applied Cryptographic Research.
If interested please go to our application form on-line. https://www.iqc.ca/positions/postdocapp/postdocapp.php
The deadline for receiving applications is 15 November 2006.
Applications may be processed as they are received. Late applications will be accepted as long as positions are still available.

and, hoisted from the comments,

Perimeter Institute for Theoretical Physics is seeking postdoctoral applicants in the areas of:
o Quantum Information Theory
o Quantum Gravity
o String Theory
o Cosmology
o Foundations of Quantum Theory
o Condensed Matter Physics
o Elementary Particle Physics
Perimeter Institute is located in Waterloo, Ontario, Canada and offers a dynamic, multi-disciplinary research environment with much freedom. Successful candidates will benefit from mentorship by Faculty, ability to invite visitors, opportunity to organize innovative conferences and workshops, access to substantive travel funds, supervision of students, optional participation in scientific committees, assistance from PI’s administrative team, as well as enjoying the productive research atmosphere and amenities of the award winning facility.
The postdoctoral positions are normally for a period of three years. Outstanding candidates may also be considered for a senior postdoctoral position with a five-year term. Exceptional applicants are encouraged to apply by November 15th, 2006. Full details and application forms are available at www.perimeterinstitute.ca.
The Institute is presently staffed with 61 resident researchers including 10 Faculty and 8 Associate Members. Currently, there is a complement of 28 Postdoctoral Researchers and a very active Visitor Program including 15 Long Term Visitors with expectations of hosting some 300 scientists throughout this academic year. A list of Visitors and other researchers is available at www.perimeterinstitute.ca/people/

Help feed the blackberry hole!

Measurement-Based Conference

The fact that you can perform unitary quantum evolutions using simple (adaptive) measurements is, to a physicist, an unexpected result. Indeed, it could be that there is no unitary evolution in the universe, only measurements! If you’re interested in measurement based quantum computing, you might be interested in conference advertised below:

International Workshop on Measurement-based Quantum Computation (MBQC07)
St. John’s College, Oxford
18 – 21 March 2007
http://www.qunat.org/workshop/
Measurement-based quantum computing (MBQC) is an active and rapidly growing area of research. The formalism of graph states (or cluster states) has proven to be a powerful way of describing the essential entanglement resources needed to perform quantum information processing tasks. Initially conceived for systems such as optical lattices and linear optical computing, this theory is now shaping the latest experimental proposals across the full spectrum of QIP technologies. A key theme of this workshop will be to foster dialog between theoreticians involved in MBQC and the experimentalists who are positioned to embrace and implement the new ideas.
Registration is open until November 30th and the number of participants will be limited to 50.

SFI Postdocs

This is a bit late being posted, but the Santa Fe Institute is running their postdoc search this year. SFI has always had a running interesting the border between physics and computer science and was even crazy enough to hire a crazy theorist like me as a postdoc. Oh, how I miss those green chiles. Here is the information for the positions, which I highly recommend quantum computing people to consider as an option. Plus you’ll get to live in New Mexico and eat lots of awesome New Mexican food and go skiing at the ever awesome Taos ski area (not to mention that the UNM and Los Alamos quantum computing groups are but a short drive away):

POSTDOCTORAL FELLOWSHIP OPPORTUNITIES
The Santa Fe Institute (SFI) anticipates offering several Postdoctoral Fellowships to begin in September 2007.
The Postdoctoral Fellowship program provides up to three years of support for independent research at SFI. Postdoctoral Fellows are encouraged to engage research questions of their own design, and to form collaborations with members of the faculty, other SFI postdocs, and researchers from around the world. Fellows pursue research that lies at the boundaries of the traditional academic disciplines, and that creates new fields of inquiry.
In addition to salary, health benefits, and retirement contributions, Fellows have access to funds to support travel to meetings, to visit collaborators at other institutions, and to bring collaborators to visit SFI. Fellows are encouraged to participate in all SFI activities, to invite speakers for the colloquium series, and to organize workshops and working groups.
Research at SFI is integrative, and there are no formal programs or departments. Individual research projects draw input from a variety of fields, including biology, chemistry, computer science, physics, mathematics, economics, sociology, anthropology, and political science. We welcome applications from any of these fields, as well as others not listed here. Descriptions of the research interests of the faculty and current Postdoctoral Fellows can be found at http://www.santafe.edu/research/researchers.php. Most research at SFI focuses on theoretical and computational approaches, although applicants whose research includes an experimental or data-collection component in collaboration with off-site colleagues are also encouraged to apply.
Candidates should have a Ph.D. (or expect to receive one by September 2007), a strong academic record, and a proven ability to work independently. We are particularly favorable toward applicants with an interest in trans-disciplinary interactions and collaboration, and who have demonstrated the potential to think outside traditional paradigms.
Applications are welcome from candidates in any country. Women and minorities are especially encouraged to apply. Successful foreign applicants must acquire an acceptable visa (usually a J-1) as a condition of employment
TO APPLY: Please view the full position announcement and application instructions at http://www.santafe.edu/education/postdocinst07.php. For full consideration, please submit all application materials, including three letters of recommendation, by November 15, 2006. For further information, please e-mail postdocinfo[at]santafe.edu.

Quantum Percent Sign?

Okay, so when we talk about classical systems, our description of the configuration of the different states is given by a probability. So I might say my bit is a mixture of 50% 0 and 50% 1. Now when we move to quantum theory we no longer have probabilities but instead have complex numbers. But what symbol am I supposed to use for this? My state is a mixture of 1/sqrt(2) q% 0 and 1/sqrt{2} q% 1? Mabye we should invent a new symbol which is the % sign but with the slash the other direction? Or turn those 0s in the % sign into “q”s?

QIP 2007 Deadlines Approaching

Michel Nielsen passes along and email detailing the fact that the deadlines for QIP 2007, to be held in Brisbane, Australia, are fast approaching:

QIP 2007
The tenth QIP (Quantum Information Processing) Workshop is to be held in
Brisbane, Australia, from January 30 through February 3, 2007. QIP covers
theoretical aspects of quantum information science, including quantum
computing, quantum cryptography, and quantum information theory.
The deadline for abstract submission for contributed talks (long and
short) and for posters is 4 November, 2006.
The deadline for early bird registration is 24 November, 2006.
Some partial support available for students and postdocs will be available
(see the website).
Full details are available at the workshop website:
http://qipworkshop.org/
Links to past QIP workshops (including programs) are available at the
website. Note that this year’s program will follow a similar format to
QIP 2006, with approximately 10 invited talks, and 30 contributed talks.
Hope to see you in Brisbane in 2007!

I have to decide whether I’m going to be able to make it this year as I’m teaching Data Structures next term. Two years in a row missing QIP sounds really bad to me.

A PR Battle Worth Fighting?

Yoinked from the comments of my post laugh therapy, John Preskill weighs in with a wise remark:

…But actually it is nice, for those of us who may have come to take the theory of quantum fault tolerance for granted, to be reminded of how truly remarkable and marvelous it is. This paper does not lay a glove on the theory. Even so, let’s be careful not to be too smug. We sure have a long way to go toward turning the theory into practice.

Indeed! My first reaction is always to act like I’m a book critic, and to crank up my hyperbole meter to overdrive. But I certainly agree with John that we should not be too smug. To destroy a line from a baseball movie, “Until we build it, they won’t come.” Indeed to me the best critique of quantum error correction is simply “you haven’t done it yet” to which I can only nod my head in agreement and then run over to the experimentalists and cheer them along.
But John’s comment got me thinking (again) about the relationship quantum computing theory has with the physics community. Certainly I don’t think there has been much of a change in the hiring practices of U.S. physics departments when it comes to quantum computing theorists. In two words: “not good.” And I wonder if perhaps one of the reasons for this is that the central message of the threshold(s) theorem(s) has not penetrated into physics. Indeed, in my mind, the threshold theorem for quantum computation is essentially a statement about a new phase of many-body quantum systems. But to many physicists, I’ll bet that the result, if they’ve heard anything about it at all, sounds more like a strange engineering/computer science result, and the inclussion of the word “theorem” sets off their antimathematical radar detection system.
In some ways what I’m saying is that it feels like we’ve lost the public relations battle in publicizing the significance of the threshold theorem to physics departments. Perhaps part of this is because the language used to describe the theorem is more often devoid of terms physicist would like to see. Indeed when I talk about the threshold theorem I always always immediately transport myself into computer science speak. But that doesn’t mean that there isn’t a beautiful way to cast the result in terms of the physics of many-body quantum systems. Should we be making fault-tolerance more accessible to physicists? Maybe this is a PR battle we should be trying harder to overcome!
Okay this is strange. Just as I was about to post this, an email popped into my inbox about the APS March meeting:

TGQI is also organizing a tutorial on Quantum Error Correction and Fault-Tolerant Quantum Computation, which will be given on Sunday, March 4, with Daniel Gottesman of the Perimeter Institute as the instructor. To attend a tutorial, you must pre-register for the Meeting.

Sounds like a good way to convert some physics skeptics!

Pre-Dewiging Pictures

Last week, after going to Innsbruck, I attended the QIPC Workshop in London. The workshop was held at the Royal Society of London and the theme was “Physicists and Computer Scientists Unite!” Scott Aaronson and I were asked to open up the workshop, and, because we are two entirely shameless people we decided that the best way to do this was, given the locale, to replace the debate between physicists and computer scientists with an opening debate between Newton and Leibnitz. Scott has posted our opening dialogue here and the talk which followed it here. And, even more importantly, and to most embarass ourselves, I now present to you incriminating evidence (thanks Viv!) that Scott and I are indeed crazy enough to mock these two great scientists by wearing the appropriate attire:
Newton and Leibnitz 2
If you look closely at the following picture, you’ll see that Scott is on the ground groveling before Newton:
Newton and Leibnitz
And finally, here we make fun of a cookie name
Newton and Leibnitz 3

Laugh Therapy

Oh, my brain is sore. Why, oh why do I get suckered into reading things like quant-ph/0610117? Now I could go on and on about this paper, but instead I thought I’d cut and past my favorite parts. The parts that didn’t make me want to send my head straight through my monitor. Mother always said if you can’t say anything nice about a paper, cut and paste the better parts and make funny statements about them. Call it laugh therapy, if you will.
Okay, let’s begin the therapy. This part is funny. It gives what I call an “argument by ignorance”:

On the other hand, the heavy machinery of the theoretical quantum computation with its specific terminology, lemmas, etc, is not readily accessible to most physicists, including myself.

So you want to criticize fault-tolerant quantum computation, but you readily admit that you do not understand it? Ha! That just cracks me up. Is this sort of like the arguments that “math is useless” because “I haven’t used math in years?” Oh, and having read the literature, I’m pretty sure that even a physicist should be able to understand it. I mean, I’m a physicist and I understand it…and I’m not even a string theorist.
Another good part of the paper is reference [19]:

The future quantum engineer is a mythical personage, who will finally achieve factorization of numbers like [tex]$10^{260}$[/tex].

Now, if I hadn’t just read the statement of ignorance which opens up this paper, I might assume that this is an ironic statement. But just having stated that things like “lemmas” are too complicated, I just can’t make that assumption. And when you say that factoring “requires” exponential time, I can’t assume that you know pretty much anything about computer science or discrete math. So I’d like to say that even today there are engineers who can factorize these numbers. Indeed [tex]$10^{260}=2^{260} times 5^{260}$[/tex].
Here is another good one:

Alicki [21] has made a mathematical analysis of the consequences of finite gate duration. I am not in a position to check his math, but I like his result: the fidelity exponentially decreases in time.

Sweet. That’s an argument by ignorance followed by an argument by “I like it!”
A Fox News bifecta!
Argh. #@%@!! Yep, that’s about all I can say.