Quantum thermal equilibration from equipartition
Institute of Physics, University of Augsburg - Universitätstr. 1, D-86159 Augsburg, Germany
2 Fachbereich Physik, Universität Osnabrück - Barbarastrasse 7, D-49069 Osnabrück, Germany
Accepted: 27 April 2012
The problem of mutual equilibration between two finite, identical quantum systems, A and B, prepared initially at different temperatures is elucidated. We show that the process of energy exchange between the two systems leads to accurate equipartition within energy shells in the Hilbert space of the total non-interacting, composite system, A⊗B. This scenario occurs under the general condition of a weak interaction between the systems. We predict that the sole hypothesis of such equipartition is sufficient to obtain a relaxation of the peers, A and B, towards a common thermal-like state. This conjecture is fully corroborated by an exact diagonalization of several quantum models.
PACS: 05.30.-d – Quantum statistical mechanics / 03.65.Aa – Quantum systems with finite Hilbert space
© EPLA, 2012