Maxwell’s demon in the quantum world
Date: Monday, February 14, 2011 @ 23:33:08 UTC Topic: Science
Juan M. R. Parrondo and Jordan M. Horowitz
Departamento de Física Atómica, Molecular y Nuclear and GISC, Universidad Complutense de Madrid, 28040Madrid, Spain
Physics 4, 13 (2011)/Published February 14, 2011
Extraction of work from a heat bath using the Szilard engine depends crucially on the statistics of indistinguishable particles.
A Viewpoint on: Quantum Szilard Engine
Sang Wook Kim, Takahiro Sagawa, Simone De Liberato, and Masahito Ueda
Phys. Rev. Lett. 106, 070401 (2011) – Published February 14, 2011
Information and thermodynamics are intimately connected. This idea was
first illustrated by Maxwell with his celebrated demon: an intelligent
being who uses his knowledge about the position and velocity of the
molecules in a gas to transfer heat against a temperature gradient
without expenditure of work, beating the second law of thermodynamics.
The Szilard engine is a stylized version of the demon, where a yes/no
measurement of a classical singleparticle system allows one to extract a
tiny amount of energy, kT ln2, k being the Boltzmann constant, from a thermal reservoir at temperature T. The engine has been around for almost a century now [1].
Along the way it has furnished insight into the foundations of
statistical mechanics, become the canonical model for investigations of
feedbackcontrolled systems, and even spurred the creation of a new
field: the thermodynamics of computation...
More: http://physics.aps.org/articles/v4/13

