Teleportation? Beam Me Up, But Do It Coherently?

This news article, led me to this website, describing a scheme (arXiv:0706.0062, “Teleportation of massive particles without shared entanglement” A. S. Bradley, M. K. Olsen, S. A. Haine and J. J. Hope) for transporting matter waves between two remote BECs. The basic idea is a setup where mater wave gets converted into information in photons which then gets written back onto another BEC. A very cool idea (if probably experimentally challenging!) However, in all of the above the articles, the experiment is described as “teleportation.” Now don’t get me wrong, I think the experiment would be very cool if you could pull it off, but does this type of setting really deserve the moniker of “teleportation”? Now normally I would call a setup like what they authors describe a quantum state transfer protocol and not teleportation. In teleportation you use entanglment and classical communication to transmit quantum information. In the above setting you swap the information from the matter wave to the light field and then back out again, with no use of entanglment or classical communication. The authors, probably sensing the existence of 32-year-old-curmudgeons like me, write

Although our scheme is quite distinct from what is normally termed quantum teleportation,
we feel that it is closer in spirit to the original fictional concept and so will use the term to describe our system.

Okay, so we could argue about this nomenclature until we turn ourselves into chemists. But the real question, I think, is not one of naming rights (although seeing as how the preprint is PRL pages long, and that damn APS journal is the king of the pedantic, there might be some interesting editor/author wrestling matches ahead.) No, the real question is whether the experiment described above is actually close in spirit to the original fictional concept!
So which is more like Star Trek teleportation? The teleportation ideas of Bennett et al. which use entanglement and classical communication or the “teleportation” ideas described above?

Reviewing Ratio?

Since that last poll got more than three total responses, and I’m here refereeing a paper, here is another poll for your amusement:
[poll=3]

Many Links Interpretation of Nature Magazine

If you haven’t seen it already, the front page of the July 5th issue of Nature has an amusing picture inspired by the “Many Worlds” interpretation of quantum theory. (I’ve said it before, and I’ll say it again. One world is enough for me, thank you very much.) Included in this issue is an essay on the many worlds interpretation:

All three approaches have their adherents, but for what seems to be a growing number of physicists, especially those working in quantum information and cosmology, it is Everett’s alternative that wins out…

Hmm, well we can run an experiment, err, I mean a social science experiment, aka a poll. Okay so these categories are subject to interpretation. For a rough guide here is wikipedia’s interpretation of quantum theories page.
[poll=2]
Also in this issue is an article Many lives in many worlds by Max Tegmark arguing for the many-worlds interpretation as well as an article Surfing the multiverse by Gary Wolfe describing many worlds and science fiction.
Finally, and perhaps more exciting than all this many worldliness, in this universe it appears that low enegy acoustic plasmons at metal surfaces have been observed. Word as to whether this observation has been made in other universes awaits the construction of a quantum computer 😉

FOCS 2007, 4 Quantum

The list of FOCS 2007 papers has been posted (via Geomblog). Quantum papers:

Andrew M. Childs, Leonard J. Schulman and Umesh V. Vazirani.
Quantum algorithms for hidden nonlinear structures
[arXiv:0705.2784]
Oded Regev and Ben Toner.
Simulating Quantum Correlations with Finite Communication
[not available online yet 🙁 ]
Dorit Aharonov, Daniel Gottesman, Sandy Irani and Julia Kempe.
The power of quantum systems on a line
[arXiv:0705.4077]
Andris Ambainis, Andrew Childs, Ben Reichardt, Robert Spalek and Shengyu
Zhang.
Any AND-OR formula of size N can be evaluated in time N^{1/2+o(1)} on a quantum computer
[arXiv:0704.3628 and arXiv:quant-ph/0703015]

QEC'07 Speaking/Poster Spots Open

From Daniel Lidar, spots open for contributed speakers at QEC’07:

There are still contributed speaker and poster slots left for QEC’07. We
would very much appreciate your assistance in spreading the word and
helping us make the conference a success. Please encourage your
students/postdocs/colleagues to submit an abstract and participate in
the conference. All pertinent information is available on the conference
site http://qserver.usc.edu/qec07/. The registration and payment deadline is Oct. 31, 2007.
With best wishes, and looking forward to seeing you at USC in December,
Daniel, Todd, and Paolo

SciRate.com Comments

Okay, so yeah, yeah, I’m going to blabber on about SciRate.com again. So if your one of those grumps who think that Digg is what you do in the dirt and MySpace refers to your own personsal space, you can stop reading now.
For those of you who haven’t checked out SciRate.com recently, you might not know that there is now a comment feature where you can comment on each paper posted. While there have only been a few comments so far, I think most readers of this blog (all three of you!) would be interested in each of these comments. So here is a digest of some recent comments:

User tobiasosborne writes a comment about 0705.0556, “Random Unitaries Give Quantum Expanders” by M. B. Hastings giving us a good expanded synopsis of the signfigance of this paper.
User Steven reads 0706.1966 so that we don’t have to.
User matt.hastings points us to 0706.3612, “Chiral entanglement in triangular lattice models” by D. I. Tsomokos, J. J. Garcia-Ripoll, and J. K. Pachos, which describes a model which just might be a chiral spin liquid.
User dabacon (now who could that be?) comments on the title of 0707.0021, “Fault Tolerant Adiabatic Quantum Computation” by Daniel A. Lidar, which he finds reason to object to. Update: And a conversation ensues.

Pretty cool, eh? Well I think it is cool, but then again, I think science benefits from open discussion (and I wrote the damn website myself, heh.)

Pardon the Interuption

But the president of the United States of America really pisses me off. Okay, and now back to your regular scheduled program: “Extreme Hidden Subgroups.”
Update: If, like me, thinking about this only makes you angry, a great therapy is to read Chad’s Bush Commutes Pluto’s Sentence.