Transport in open spin chains: A Monte Carlo wave-function approach

TL;DR

This paper studies energy transport in open spin chains using a quantum master equation and Monte Carlo wave-function method, revealing diffusive or ballistic behavior and insights into infinite system limits.

Contribution

It introduces a Monte Carlo wave-function approach to analyze nonequilibrium energy transport in spin chains based on a recent quantum master equation.

Findings

Identifies conditions for diffusive vs. ballistic transport.

Provides a method to extrapolate transport behavior to infinite models.

Demonstrates the effectiveness of the Monte Carlo wave-function approach.

Abstract

We investigate energy transport in several two-level atom or spin-1/2 models by a direct coupling to heat baths of different temperatures. The analysis is carried out on the basis of a recently derived quantum master equation which describes the nonequilibrium properties of internally weakly coupled systems appropriately. For the computation of the stationary state of the dynamical equations, we employ a Monte Carlo wave-function approach. The analysis directly indicates normal diffusive or ballistic transport in finite models and hints toward an extrapolation of the transport behavior of infinite models.