Evidence for a large magnetic heat current in insulating cuprates

TL;DR

This study reveals that in insulating cuprates, magnetic excitations significantly contribute to in-plane thermal conductivity at high temperatures, indicating a large magnetic heat current intrinsic to these materials.

Contribution

It provides experimental evidence for a substantial magnetic heat current in insulating cuprates, highlighting the role of magnetic excitations in thermal transport.

Findings

Magnetic excitations contribute significantly to thermal conductivity at high temperatures.

Phonons dominate heat transport at low temperatures.

Large magnetic heat current is an intrinsic property of layered cuprates.

Abstract

The in-plane thermal conductivity $k$ of the two-dimensional antiferromagnetic monolayer cuprate Sr$_2$CuO$_2$Cl$_2$ is studied. Analysis of the unusual temperature dependence of $k$ reveals that at low temperatures the heat is carried by phonons, whereas at high temperatures magnetic excitations contribute significantly. Comparison with other insulating layered cuprates suggests that a large magnetic contribution to the thermal conductivity is an intrinsic property of these materials.