Thermalization of quantum systems by finite baths

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

Corresponding author: jgemmer@uos.de

Received: 15 July 2005
Accepted: 31 October 2005

Abstract

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.