Strong evidence of normal heat conduction in a one-dimensional quantum system

Department of Applied Physics, School of Engineering University of Tokyo - Bunkyo-ku, Tokyo 113-8656, Japan

Received: 7 June 2002
Accepted: 10 October 2002

Abstract

We investigate how the normal energy transport is realized in one-dimensional quantum systems using a quantum spin system. The direct investigation of local energy distribution under thermal gradient is made using the quantum master equation, and the mixing properties and the convergence of the Green-Kubo formula are investigated when the number of spin increases. We find that the autocorrelation function in the Green-Kubo formula decays as to a finite value which vanishes rapidly with the increase of the system size. As a result, the Green-Kubo formula converges to a finite value in the thermodynamic limit. These facts strongly support the realization of Fourier heat law in a quantum system.