Author: dabacon

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So You Want to Build an Atomic Clock

Via Paul: Till Rosenband from the Time and Frequency Division of NIST has released as open source software that they use to control some of their atomic physics ion trap experiments:

Ionizer

Summary:

Control-software for atomic physics experiments in ion traps.
LaserBrothers software automatically re-locks lasers to reference cavities, and doubling-cavities to lasers.
Aluminizer software controls the NIST aluminum ion clock. This is an application with a graphical front-end (client) to an FPGA-based pulse-sequencer (server). Pulse-sequences are written as object-oriented C++ programs with timing resolution of 10 ns and jitter of about 1 ns. Many calibrations are performed automatically. This program is written specifically to control the NIST Al+/Mg+ clock, but effort was made to keep the code general enough to adapt to other tasks.
LabAC software controls a laboratory air-conditioning system. THIS CODE HAS NOT YET BEEN UPLOADED.
BullsIon software shows the coordinates of a laser-beam that’s on a webcam. THIS CODE HAS NOT YET BEEN UPLOADED.

So if you happen to be a tech mogul who has enough dollars to start your own lab, this looks like some good stuff for setting up your own ion trap experiments 🙂

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Damn Minus Signs

A new entry in the best title ever contest, via Steve, arXiv:1002.0555:

A minus sign that used to annoy me but now I know why it is there

Authors: Peter Tingley

Abstract: We consider two well known constructions of link invariants. One uses skein theory: you resolve each crossing of the link as a linear combination of things that don’t cross, until you eventually get a linear combination of links with no crossings, which you turn into a polynomial. The other uses quantum groups: you construct a functor from a topological category to some category of representations in such a way that (directed framed) links get sent to endomorphisms of the trivial representation, which are just rational functions. Certain instances of these two constructions give rise to essentially the same invariants, but when one carefully matches them there is a minus sign that seems out of place. We discuss exactly how the constructions match up in the case of the Jones polynomial, and where the minus sign comes from. On the quantum group side, we are led to use a non-standard ribbon element.

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Two Interesting LaTeX Online Editors

One, a Google Docs app, LaTeX Lab (thanks to Daniel for pointing this out.) Another with https support Verbosus. I couldn’t get the later to compile and display in browser with FireFox, but did in Safari. Verbosus has an android app, but strangely no desktop version.
Recently I’ve been mostly using Dropbox for collaborations using LaTeX. Every once in a while there are conflicts in editing at the same time, but with only a few people this seems to work really well.

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Uniquity Symposium on "What is Computation?"

Readers of the Pontiff might be interested in a series of articles coming out in the ACMs Ubiquity publication concerning the question: “What is Computation?” Over the next 15 weeks the following articles will come out on this subject including one by a jokester:

The following articles will appear on Ubiquity once a week, beginning in November 2010.
1. What is Computation? [opening statement], by Peter J. Denning
2. Evolution of Computation, by Peter Wegner
3. Computation is Symbol Manipulation, by John Conery
4. Computation is Process, by Dennis J. Frailey
5. Computing and Computation, by Paul Rosenbloom
6. Computation and Information, by Ruzena Bajcsy
7. Computation and Fundamental Physics, by Dave Bacon
8. The Enduring Legacy of the Turing Machine, by Lance Fortnow
9. Computation and Computational Thinking, by Al Aho
10. What is the Right Computational Abstraction for Continuous Scientific Problems? by Joseph Traub
11. Computation, Uncertainty, and Risk, by Jeffrey P. Buzen
12. Natural Computation, by Erol Gelenbe
13. Biological Computation, by Melanie Mitchell
14. Is the Symposium Question Harmful? by Peter Freeman
15. Wrapping it Up [closing statement], by Peter J. Denning

I suppose this is a paper dance of some sort, but I’m guessing its one with me dancing around saying “One of these kids is not like the others.”

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Quantum Communications at CLEO 2011

Richard Hughes send along a call for contributed papers for the Quantum Communications Symposium at CLEO2011:

Call for contributed papers: Quantum Communications Symposium, CLEO2011

1-6 May, 2011, Baltimore, MD

http://www.cleoconference.org/

Deadline for submissions: December 2, 2010 at 1700GMT

Dear Colleagues,

Tom Chapuran (Telcordia), Norbert Lutkenhaus (Waterloo), Iain McKinnie (Kapteyn Murnane Labs) and I are organizing a Quantum Communications Symposium at CLEO2011: http://www.cleoconference.org/conference_program/symposia.aspx

We are close to finalizing an outstanding line-up of invited talks from internationally-leading quantum communications researchers. At this time we are issuing a call for contributed papers to the symposium: please consider submitting your latest quantum communications research results at: http://www.cleoconference.org/submissions/Electronic_Submissions.aspx

To have your contribution considered for the symposium, please submit it to one of the following subcommittees:

CLEO:QELS – Fundamental Science 2: Quantum Science, Engineering and Technology;

CLEO: Science & Innovations 12: Lightwave Communications and Optical Networks;

CLEO: Applications & Technology 3: Government & National Science, Security & Standards Applications

no later than 1700GMT December 2, 2010.

Thanks,

Richard Hughes

Physics Division, LANL

*******************************************************

Quantum Communications Symposium description:

Quantum communications is a rich interdisciplinary field encompassing fundamental science, innovative technologies, and a broad range of potential applications to computing, cryptography, and networking. Since the first experiments two decades ago, the transmission of quantum states has been extended to ranges of hundreds of kilometers, in optical fiber and in free space. Novel optical networking techniques have been developed to enable scalable communications among large numbers of users. Investigations of entanglement, teleportation, and other uniquely quantum phenomena have provided fundamental insights into the quantum world, while also laying critical groundwork for the development of quantum repeaters. Theoretical research has led to the emergence of wholly new cryptographic paradigms and applications, such as quantum key distribution, quantum secure identification and quantum secret sharing, whose security assurances are rooted in the laws of physics. Large-scale quantum communications testbeds have been demonstrated in recent years in several countries, and commercial standards activities are underway. The symposium will highlight the latest research results across the broad spectrum of quantum communications topics from fundamental science to practical applications. It will provide an overview of quantum communications in optical fiber networks and free-space, including the underlying science, components and technology impacting systems, networks, and field trials, with invited presentations from leading research groups around the world.

Organizers:

Thomas Chapuran, Telcordia

Richard Hughes, Los Alamos National Lab

Norbert Lütkenhaus, Univ. of Waterloo

Iain McKinnie, Kapteyn Murnane Labs

CLEO2011 blog:

http://cleoqels2010.blogspot.com/

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GIANTS!

Freaks, beards, panda bears.  Aubrey, Buster, Timmy.  Hell yeah, the SF GIANTS are world series champions!!!!  GIANTS!!!
For some reason, the only words that really come to mind are the opening lines to a place just down the road from San Francisco, a place called “Cannery Row”:

Cannery Row in Monterey in California is a poem, a stink, a grating noise, a quality of light, a tone, a habit, a nostalgia, a dream. Cannery Row is the gathered and scattered, tin and iron and rust and splintered wood, chipped pavement and weedy lots and junk heaps, sardine canneries of corrugated iron, honky tonks, restaurants and whore houses, and little crowded groceries, and laboratories and flophouses. Its inhabitants are, as the man once said, ‘whores, pimps, gamblers and sons of bitches,’ by which he meant Everybody. Had the man looked through another peephole he might have said, ‘Saints and angels and martyrs and holy men,’ and he would have meant the same thing.

Truly a team of Everybody, sinners and saints (and a few good pitchers), scratched and clawed their way past teams five time their size this post season to win the first world series in San Francisco history.  In typical San Francisco fashion they looked nothing like you’d expect, were assembled from the dregs the rest of the nation threw out, and destroyed the predictions made by certain East coast pundits who shall remain nameless.  Tonight in San Francisco they will celebrate!
Hell the high (vote yes on 19?) might even last long enough that their leftist butts won’t even feel the pain of the November 2 election 😉

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Quantum Jobs in the DC Area

Some more quantum jobs.

Booz Allen Hamilton in DC area (a contact is Mark Bowman, bowman_mark [atathereisanat] ne dot bah dot com):

Booz Allen Hamilton is seeking a skilled computer scientists to provide technical support for clients in the Washington, DC area.  An advanced degree with a research background in the following areas is desired: programming language design, compiler theory, software engineering, error correcting codes, and optimal control theory.  See their announcement at https://bah.taleo.net/careersection/10020/jobdetail.ftl.

SAIC in DC area:

Quantum Information Scientist (SAIC Arlington VA)

SAIC has an opening for a physicist, or computer scientist with research experience in quantum computing or quantum information science. Areas of interest include: device and condensed matter theory: (superconducting devices, ion-traps, quantum dots), quantum simulation, quantum algorithms, and quantum error correction. Experience in the design and operation of qubit devices is desired. Knowledge of techniques for implementing quantum algorithms within realistic settings is also desired.

In the area of quantum simulation, expertise in the theory of using quantum computers to simulate other quantum systems is desired, as well as experience in techniques to simulate quantum computation on classical computers.

The candidate must have a track record of doing exceptional research in quantum computing and/or quantum information. The position entails performing theoretical and applied research in quantum information science within a small academic-style research and development group.

The position requires a Ph.D. in physics, computer science, or related field and direct experience in quantum computing and/or quantum information. Postdoctoral experience is preferred but not required. Experience with programming languages and tools including: Matlab, Mathematica, C++, C, or Fortran is desired.

The candidate must be able to obtain a Top Secret DoD security clearance. The work will be performed at SAIC in Arlington Virginia, and relocation assistance is available. A small amount of domestic travel may be required.

To apply for this position please visit the SAIC career site at http://www.saic.com/career/ and
search for the position “Quantum Information Scientist”

 

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Post Quantum Cryptography

Today I’m at the Joint Quantum Institute attending a workshop on quantum computing.  This morning’s session is on “post quantum cryptography.”  Post quantum cryptography is the study of classical (public key) cryptosystems which could replace the plethora of cryptosystems that quantum computers break (RSA, Diffie-Hellman, elliptic curves.)  These new systems include lattice based cryptography, the McEleise crypstosystem, and more (The name is kind of confusing, because post quantum cryptography, to me, sounds like the study of cryptosystems based on possible extensions or modifications of quantum theory, but that’s probably just because I spend too much time listening to foundations of quantum theory folks 🙂 )  Of course as a quantum computing person, my interest mostly is in hearing about problems that I can try to crack using a quantum computer 🙂

RSA and its ilk have a security that is based upon the computational difficulty of problems that now have a long history of study (factoring, discrete logarithm, etc.)  While it is completely possible that there is an efficient classical algorithm for factoring, a lot of our confidence in this not being true is based upon the large amount of effort that has been put into solving this problem.  We could even define a quantity: the integrated number of theorist hours spent on the problem.  This is certainly a very large number.  How large?  Well one probably has to know the size of the National Security Agency’s payroll to calculate it, but even in the public sphere this number is pretty high.  So for the post quantum cryptography world, the new (or old, but now more relevant) cryptosystems that have been proposed, we could also calculate this number.  More interestingly we could try to calculate this number for people working on quantum attacks on these problems.  I think I could actually do this calculation myself, as I know most of these people (or at least the ones in the public sphere), and even something about their working habits 🙂  But this is certainly a very very small number.  So it seems to me that if one really wants to study post quantum cryptography, one needs to invest heavily not just in people classically attacking the problems, but also in quantum theorists attacking the problem in order to insure confidence that this is truly “post quantum.

So…um, it seems that there is a very strong need to establish a very large effort in quantum algorithms, not just because we’d like to know what else quantum computers are good at, but also because we need to make sure “Shor, part II” doesn’t occur and the post quantum cryptography systems that are deployed aren’t themselves vulnerable to quantum attack.  I was at a program review recently where a speaker who funds quantum computing got up and said roughly “I got into quantum computing because it scared me.  What I want to see today is more things that scare me.”  Damn straight, but in practice I worry that the size of the effort directed this way in quantum computing is not nearly large enough.  The U.S. in particular has a severe dearth of quantum computing theorists, or at least such theorists who advance beyond the graduate student / postdoc level.

So post quantum cryptography is great, but it needs to be really “post quantum.”  And that scares me, because I look around and just don’t see the basis for a concerted effort to insure the security of these new cryptosystems against quantum attacks.

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The Giants Win the Pennant! The Giants Win the Pennant!

Okay, not quite as memorable, but the fan going nuts below is how I felt with my SF Giants going to the World Series:

I think I learned some of my first swear words in Candlestick park, growing up with Jeffrey Leonard, Jose Uribe, Will “the Thrill” Clark, and friends. The Bonds years were interesting, but I’m glad to see this new bunch of Giants. Brian Wilson is, as far as I can tell, absolutely crazy. Buster Posey has no idea he should be scared to death. And man, this team is completely and totally CLUTCH.
Go Giants!!!!