Transport in dimerized and frustrated spin systems

TL;DR

This paper investigates spin and thermal transport in one-dimensional spin-1/2 systems, showing that non-integrable models tend to exhibit normal transport behavior as system size increases.

Contribution

It provides evidence that Drude weights vanish in the thermodynamic limit for non-integrable models, indicating a transition from ballistic to diffusive transport.

Findings

Drude weights are non-zero for finite systems.

Drude weights tend to vanish in the thermodynamic limit for non-integrable models.

Normal (diffusive) transport behavior is implied in large systems.

Abstract

We analyze the Drude weight for both spin and thermal transport of one-dimensional spin-1/2 systems by means of exact diagonalization at finite temperatures. While the Drude weights are non-zero for finite systems, we find indications of a vanishing of the Drude weights in the thermodynamic limit for non-integrable models implying normal transport behavior.