Boundary conditions for quantum lattice systems

verfasst von

M. Fannes, R. F. Werner

Abstract

For classical lattice systems, the Dobrushin-Lanford-Ruelle theory of boundary conditions states that the restriction of a global equilibrium state to a subsystem can be obtained as an integral over equilibrium states of the subsystem alone. The Hamiltonians for the subsystem are obtained by fixing a configuration for the variables in the complement of the subsystem, or more generally, by evaluating the full interaction Hamiltonian with respect to a state for the complement. We provide examples showing that the quantum mechanical version of this statement is false. It fails even if the subsystem is classical, but embedded into a quantum environment. We suggest an alternative characterization of the local restrictions of global equilibrium states by inequalities involving only local data.

Organisationseinheit(en)

Institut für Theoretische Physik

Externe Organisation(en)

KU Leuven

Typ

Artikel

Journal

Helv. Phys. Acta

Band

68

Seiten

635-657

Anzahl der Seiten

23

Publikationsdatum

1995

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja