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Thermodynamics of information processing: A minimal model of an autonomous Maxwell Demon

TYPECondensed Matter Seminar
Speaker:Prof. Christopher Jarzynski
Affiliation:University of Maryland
Date:19.06.2012
Time:14:30
Location:Lidow Nathan Rosen (300)
Abstract:

The thermodynamic implications of information processing have recently received renewed attention, in contexts such as quantum information theory, the synthesis of artificial molecular machines, and feedback control in microscopic systems.  A question at the heart of this field is whether or not the Shannon entropy of a random string of data ought to be treated as a genuine thermodynamic entropy, with consequences for the conversion of heat into work. I will address this issue by describing a model system that operates as an autonomous Maxwell Demon.  This "demon" interacts with a thermal reservoir, a stream of bits, and a mass that can be lifted or lowered.  Its dynamics are modeled with thermodynamically consistent transition rates. The steady-state behavior of the model can be solved exactly, and this solution is used to construct the nonequilibrium phase diagram as a function of the model parameters.  The demon can act either as an engine, converting heat to work (lifting the mass) while writing information to the stream of bits; or as an eraser, using the energy of the falling mass to erase information in the bit stream.  The model offers a simple paradigm for exploring the interplay between heat, work and information in small systems.