Europhys. Lett.
Volume 73, Number 1, January 2006
Page(s) 1 - 7
Section General
Published online 30 November 2005
Europhys. Lett., 73 (1), pp. 1-7 (2006)
DOI: 10.1209/epl/i2005-10363-0

Thermalization of quantum systems by finite baths

J. Gemmer1 and M. Michel2

1  Physics Department, University of Osnabrück - Barbarastr. 7 49069 Osnabrück, Germany
2  Institute of Theoretical Physics I, University of Stuttgart Pfaffenwaldring 57, 70550 Stuttgart, Germany

received 15 July 2005; accepted in final form 31 October 2005
published online 30 November 2005

We consider a discrete quantum system coupled to a finite bath, which may consist of only one particle, in contrast to the standard baths which usually consist of continua of oscillators, spins, etc. We find that such finite baths may nevertheless equilibrate the system though not necessarily in the way predicted by standard open-system techniques. This behavior results regardless of the initial state being correlated or not.

03.65.Yz - Decoherence; open systems; quantum statistical methods.
05.70.Ln - Nonequilibrium and irreversible thermodynamics.
05.30.-d - Quantum statistical mechanics.

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