'Laser Tweezers' Used to Sort Atoms

luckyguesser writes to tell us that Physicists at the University of Bonn are claiming to have knocked down one more quantum computing hurdle. Utilizing what they term "laser tweezers" they were able to sort and align seven atoms while capturing it on film. The plan is to construct a quantum gate using atoms imprinted with data.

A little more detail

[grapeape]

There is a bit more detail here, including a picture:

http://news.softpedia.com/news/The-Atom-Sorting-Ma chine-29616.shtml [softpedia.com]

Re:Niiiiiiiice

[Jerry Coffin]

One more step to kissing NP Complete good bye, and one more step to invalidating all current forms of encryption.

Nonsense. First of all, nobody's really figured out much of a way to apply quantum computers to symmetric encryption, only to most public key cryptography. There are some ideas around that the fast database lookup you can do with a quantum computer should translate to some way to break symmetric encryption faster, but most current algorithms support long enough keys to combat that already. From the viewpoint of exhausting the key space (i.e. a brute force attack) using a conventional computer, there's basically no point in a key size large than 128 bits (or even a bit less than that). Most current algorithms, however, support at least 256 bits.

Keep in mind that the difficulty of key exhaustion is exponential with respect to key size. IOW, adding one bit to the key size doubles the difficulty of key exhaustion. Adding 128 bits multiplies the difficulty by 2^128.

if u read it closely

[kasgoku]

if you read it closely, it is not exactly the normal tweezer you and me use(not really.) its kinda like throwing an atom somewhere, instead of actually lifting it and moving somewhere. you cant guarantee that it will land at the same target all the time.

University of Chicago has been doing this...

[VoidEngineer]

for at least 5 years.

Granted, it seems like their tweezers might be slightly more precise than Chicago's, but as far as I can tell, the article is little more than University of Bonn's press-release saying that they're playing in the same league. Granted, Chicago now has 5 years of experience patenting the process and developing applications with it.

http://mrsec.uchicago.edu/Nuggets/Holographic_Opti cal_Tweezers/ [uchicago.edu]

It should be noted Chicago's method is a little more "rubic's cubish" than Bonn's "conveyor belt" setup. Coupled with what is probably a different setup for the optical trap and laser mesh, and the 5 year difference in publications, I would doubt that there would be any patent conflict and that this will wind up being a competing product.

Also, my guess is that these laser tweezers are going to play a part in the design of the first functional general nanoassemblers (of the style of Enterprise's 'replicators', not of the style of a grey goo assembler).

Re:film?

[Yogurtron]

I as well was wondering this. They reference this "film" repeatedly, and no film is shown on there, nor a link to it. FINALLY somebody that notices these things too. I'm usually the only one to see such greivous errors as mentioning a film yet not having one.

Lucky for you, I'm bored at work and have access to google's translation tools. It found a part of the university that did this, and it linked to a place that DOES have films:

Film: http://www.opticsexpress.org/abstract.cfm?URI=OPEX -11-25-3498 [opticsexpress.org]

Just for reference, it was linked form here:
http://www.uni-bonn.de/Aktuelles/Presseinformation en/2003/455.html [uni-bonn.de]

Another way. mark Raizen

[XchristX]

The research group of Mark Raizen of the University of Texas at Austin has been working on similar techniques of 'tweezing' and 'laser culling'. Theoretically, in quantum tweezing, Gaussian lasers would sweep over a Bose-Einstein Condensate of ultracold atoms. The velocity of the sweep can be tuned in such a way that Landau-Zener tunnelling criterion is only satisfied for one atom in the reservoir and it tunnels into the sweeping beam.

http://prola.aps.org/abstract/PRL/v89/i7/e070401 [aps.org]

  In addition, 'laser culling' is a process by which a doppler-cooled set of atoms, kept in a MOT trap, can have the nuber of atoms whittled down by lowering the trap height. This can be done until a sub-poissionian regime is achieved and a definite number state is in the trap.

http://www.utexas.edu/opa/news/2006/01/physics04.h tml [utexas.edu]

http://www.colorado.edu/physics/2000/bec/index.htm l [colorado.edu]

Re:"Writing on individual atoms"

[liegeofmelkor]

I agree wholeheartedly. This physorg article was a convoluted mass of steaming dung. I couldn't begin to understand what the author was trying to say, or what the large improvement was over techniques that have been done for years already (some noted in comments already). I'm a physical chemist for Christ's sake! I hopped over to 'Nature,' skimmed the real article, and came to the conclusion that the author of the PhysOrg piece didn't have a firm handle on the quantum chemistry and or techniques utilized. His analogies to dumb things down for the reader were actually, imho, grasping attempts he made to sort out the process in his own mind. Additionally, the language of the physorg piece implied that author bought sales pitch the U. Bonn group gives to its funding agencies (big improvement, hurdle crossed, HUGE progress, quantum computer around the corner). True, this is an advance and it deserves the funding it gets, but it is incremental, not monumental. However in the publish or die environment that is acadamedia, progress must be... embellished. This unfortunate sap believed it!