Incoherent transport in a classical spin liquid

TL;DR

This paper investigates energy and spin transport in a classical spin liquid, revealing finite diffusion constants at zero temperature due to effective disorder and normal mode propagation.

Contribution

It introduces an effective disorder model to explain finite zero-temperature diffusion constants in a classical spin liquid.

Findings

Both energy and spin diffusion constants approach finite limits as temperature approaches zero.

Normal modes propagate in a quasi-static disordered spin background.

Finite mean free path explains the non-zero diffusion constants at zero temperature.

Abstract

We study the energy and spin transport of the classical spin liquid hosted by the pyrochlore Heisenberg antiferromagnet in the large $S$ limit. Molecular dynamics calculation suggests that both the energy and spin diffusion constants approach finite limits as the temperature tends to zero. We explain our results in terms of an effective disorder model, where the energy/spin-carrying normal modes propagate in a quasi-static disordered spin background. The finite zero temperature limits of the diffusion constants are then naturally understood as a result of the finite mean free path of the normal modes due to the effective disorder.