Thermal conductivity of quasi-one-dimensional antiferromagnetic spin-chain materials

TL;DR

This paper models heat transport in quasi-one-dimensional antiferromagnetic spin-chain materials, revealing temperature-dependent behaviors of thermal conductivity and matching experimental data for Sr2CuO3.

Contribution

It introduces a theoretical model combining spin excitations, phonons, and impurities to explain thermal conductivity in spin-chain systems, with specific temperature dependence predictions.

Findings

Thermal conductivity scales as T^2 at low temperatures.

Thermal conductivity scales as 1/T at intermediate temperatures.

Results align with experimental data for Sr2CuO3.

Abstract

We study heat transport in quasi-one-dimensional spin-chain systems by considering the model of one-dimensional bosonic spin excitations interacting with three-dimensional phonons and impurities in the limit of weak spin-lattice coupling and fast spin excitations. A combined effect of the phonon and impurity scatterings yields the following spin-boson thermal conductivity behavior: kappa_s ~ T^2 at low, kappa_s ~ 1/T at intermediate, and kappa_s = const at higher temperatures. Our results agree well with the existing experimental data for Sr2CuO3. We predict an unusual dependence on the impurity concentration for a number of observables and propose further experiments.