
Penn State scientists build quantum version of Maxwell’s demon - BerislavLopac
https://arstechnica.com/science/2018/09/penn-state-scientists-build-quantum-version-of-maxwells-demon/
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melloc
For those who don't know, the term "daemon" as used in computing is a
reference to Maxwell's demon, since it's doing its work in the background.

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mrfredward
To be clear: No one is violating the 2nd law of thermodynamics here, nor is
anyone trying. The scientists have a mechanism which reduces entropy at one
part of a system at the expense of creating more entropy somewhere else. That
mechanism could be useful in quantum computing.

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dsamarin
Does this essentially make an equivalent of a refrigerator at a quantum scale?

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olliej
My reading of this (and another article about it the other day), is that they
haven’t constructed anything, just come up with a new experimental design that
should theoretically be able to do it. Am I wrong?

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iaw
> "His team used three pairs of laser beams to trap and cool neutral
> (uncharged) cesium atoms to ultra-cold temperatures (a few degrees above
> absolute zero) in a 3D lattice with 125 positions (a 5×5×5 cube). They
> filled half the positions with atoms in random positions and then moved the
> atoms around by changing the polarization of the laser traps—the equivalent
> function of Maxwell's demon, except using position to sort them rather than
> speed. By this means, they were able to create ordered 5×5×2 or 4×4×3
> subsets within the originally disordered lattice, thereby reducing the
> system's entropy."

Quoting directly from the article, note I only skimmed it.

