2008/12/12 by Noah Linden, Sandu Popescu, Anthony J. Short +1 · 1 voice · 1 citation
Physics and Astronomy · #cond-mat.stat-mech #quant-ph
paper · pdf · doi:10.1103/physreve.79.061103
published as Phys. Rev. E 79:061103 (2009) · 12.1 pages
arxiv created 2008/12/12 · arxiv published 2008/12/12 · arxiv updated 2017/08/01
The circumstances under which a system reaches thermal equilibrium, and how to derive this from basic dynamical laws, has been a major question from the very beginning of thermodynamics and statistical mechanics. Despite considerable progress, it remains an open problem. Motivated by this issue, we address the more general question of equilibration. We prove, with virtually full generality, that reaching equilibrium is a universal property of quantum systems: Almost any subsystem in interaction with a large enough bath will reach an equilibrium state and remain close to it for almost all times. We also prove several general results about other aspects of thermalisation besides equilibration, for example, that the equilibrium state does not depend on the detailed micro-state of the bath.