German Scientists Create Bose-Einstein Condensate Using Photons 61
xt writes "A team of physicists, led by the University of Bonn's Martin Weitz, have managed to create a Bose-Einstein condensate (here's a more detailed explanation) out of photons, previously thought to be impossible. The research was published in the journal Nature (abstract, and the arXiv has the submitted paper as a PDF) and has possible applications on solar energy technology and shortwave lasers, which would be well-suited to the manufacture of computer chips as the process uses lasers to etch logic circuits onto semiconductor materials. Seems like Moore's law is safe again!"
Re:Idea (Score:2, Informative)
As the photon BEC works at room temperature and seems quite simple, [...] can't it simply be miniaturized and used as a replacement of circuitry instead of used for lithography?
Define simple.
You do realise how good the technology you want to replace really has become?
MOSFET's are reliable switches that are really, really small.
They are so small, modern transistors are composed of a number of atoms that
humans can actually imagine.
There are few other technological items that are that small, and yet fullfil a
task with incredible reliability over a long period of time as an individual device.
I actually don't know of any right now.
If you can't miniaturize these cavities to sub micrometer dimensions, they would
have to be _incredibly_ fast switches to compensate for a sheer lack of number.
Re:Moore's law is worthless right now... (Score:3, Informative)
Firefox maxes one core out all the time. I could certainly use more flops.
No, you could use a better version of Firefox. There's no reason a browser should max out a current multi-core CPU.
Re:What exactly is this? (Score:3, Informative)
It's a pretty dense article but, as far as I can tell, they're considering the motion of the photons in the plane transverse to the cavity axis as the particle movement. The problem is then two-dimensional in nature with the curvature of the mirrors directing photons back towards the cavity center. The situation is then analogous to a two-dimensional gas of particles confined by a central trapping potential.
In essence, the temperature is related to the transverse velocity of the intra-cavity photons. I believe that the cavity is spatially multi-mode and the quantum state of a photons is which spatial mode it's in and how it's evolving. Interaction with the dye particles randomizes (thermalizes) the quantum state of each photon, resulting in each photon engaging in a thermal random walk about the cavity's transverse modes. They then found the critical parameters for the "photon gas" to condense into occupying the lowest energy state (probably the fundamental Gaussian cavity mode).
Again, it's a pretty strange paper so I may have some details wrong. Fundamentally though, it's about modelling the transverse motion of photons in a cavity as particle motion, introducing thermal noise through scattering, then analyzing the dynamics by comparing to atomic motion and showing similar condensation at appropriate parameters. Quite an amazing paper.