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arXiv · 2401.01407

Heat conduction in magnetic insulators via hybridization of acoustic phonons and spin-flip excitations

Christopher A. Pocs·Ian A. Leahy·Jie Xing·Eun Sang Choi·Athena S. Sefat·Michael Hermele·Minhyea Lee
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Abstract

We present a comprehensive study on the longitudinal magneto-thermal transport in a paramagnetic effective spin-1/2 magnetic insulator CsYbSe$_2$, by introducing a minimal model requiring only Zeeman splitting and magnetoelastic coupling. We use it to argue that hybridized excitations -- formed from acoustic phonons and localized spin-flip-excitations across the Zeeman gap of the crystal electric field ground doublet -- are responsible for a non-monotonic field dependence of longitudinal thermal conductivity. Beyond highlighting a starring role for phonons, our results raise the prospect of universal magneto-thermal transport phenomena in paramagnetic insulators that originate from simple features shared across many systems.

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Christopher A. Pocs, Ian A. Leahy, Jie Xing, Eun Sang Choi, Athena S. Sefat, Michael Hermele, Minhyea Lee. 2024-01-02. Heat conduction in magnetic insulators via hybridization of acoustic phonons and spin-flip excitations. https://doi.org/10.1103/physrevresearch.7.l022007

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