Heat conduction in low-dimensional quantum magnets

TL;DR

This paper reviews recent experimental findings on magnetic heat conduction in low-dimensional quantum magnets, highlighting its significance and unique properties compared to phonon and electron heat transport.

Contribution

It provides a comprehensive summary of experimental results on magnetic thermal conductivity in various low-dimensional quantum spin models, emphasizing its unusual magnitude and scattering mechanisms.

Findings

Magnetic heat conductivity often exceeds phonon conductivity in these materials.

Distinct scattering mechanisms of magnetic excitations have been identified.

Magnetic heat transport reveals unique properties in low-dimensional quantum magnets.

Abstract

Transport properties provide important information about the mobility, elastic and inelastic of scattering of excitations in solids. Heat transport is well understood for phonons and electrons, but little is known about heat transport by magnetic excitations. Very recently, large and unusual magnetic heat conductivities were discovered in low-dimensional quantum magnets. This article summarizes experimental results for the magnetic thermal conductivity $\kappa_\mathrm{mag}$ of several compounds which are good representations of different low-dimensional quantum spin models, i.e. arrangements of S=1/2 spins in the form of two-dimensional (2D) square lattices and one-dimensional (1D) structures such as chains and two-leg ladders. Remarkable properties of $\kappa_\mathrm{mag}$ have been discovered: It often dwarfs the usual phonon thermal conductivity and allows the identification and analysis of different scattering mechanisms of the relevant magnetic excitations.