Phonon thermal transport shaped by strong spin-phonon scattering in a Kitaev material Na$_2$Co$_2$TeO$_6$

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Hong, Xiaochen, Gillig, Matthias, Yao, Weiliang, Janssen, Lukas, Kocsis, Vilmos, Gass, Sebastian, Li, Yuan, Wolter, Anja U. B., Büchner, Bernd, Hess, Christian
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913236750696448
author Hong, Xiaochen
Gillig, Matthias
Yao, Weiliang
Janssen, Lukas
Kocsis, Vilmos
Gass, Sebastian
Li, Yuan
Wolter, Anja U. B.
Büchner, Bernd
Hess, Christian
author_facet Hong, Xiaochen
Gillig, Matthias
Yao, Weiliang
Janssen, Lukas
Kocsis, Vilmos
Gass, Sebastian
Li, Yuan
Wolter, Anja U. B.
Büchner, Bernd
Hess, Christian
contents The recent report of a half-quantized thermal Hall effect in the Kitaev material $α$-RuCl$_3$ has sparked a strong debate on whether it is generated by Majorana fermion edge currents or whether other more conventional mechanisms involving magnons or phonons are at its origin. A more direct evidence for Majorana fermions which could be expected to arise from a contribution to the longitudinal heat conductivity $κ_{xx}$ at $T\rightarrow0$ is elusive due to a very complex magnetic field dependence of $κ_{xx}$. Here, we report very low temperature (below 1~K) thermal conductivity ($κ$) of another candidate Kitaev material, Na$_2$Co$_2$TeO$_6$. The application of a magnetic field along different principal axes of the crystal reveals a strong directional-dependent magnetic-field ($\bf B$) impact on $κ$. We show that no evidence for mobile quasiparticles except phonons can be concluded at any field from 0~T to the field polarized state. In particular, severely scattered phonon transport is observed across the $B-T$ phase diagram, which is attributed to prominent magnetic fluctuations. Cascades of phase transitions are uncovered for all $\bf B$ directions by probing the strength of magnetic fluctuations via a precise record of $κ$($B$). Our results thus rule out recent proposals for itinerant magnetic excitations in Na$_2$Co$_2$TeO$_6$, and emphasise the importance of discriminating true spin liquid transport properties from scattered phonons in candidate materials.
format Preprint
id arxiv_https___arxiv_org_abs_2306_16963
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Phonon thermal transport shaped by strong spin-phonon scattering in a Kitaev material Na$_2$Co$_2$TeO$_6$
Hong, Xiaochen
Gillig, Matthias
Yao, Weiliang
Janssen, Lukas
Kocsis, Vilmos
Gass, Sebastian
Li, Yuan
Wolter, Anja U. B.
Büchner, Bernd
Hess, Christian
Strongly Correlated Electrons
Materials Science
The recent report of a half-quantized thermal Hall effect in the Kitaev material $α$-RuCl$_3$ has sparked a strong debate on whether it is generated by Majorana fermion edge currents or whether other more conventional mechanisms involving magnons or phonons are at its origin. A more direct evidence for Majorana fermions which could be expected to arise from a contribution to the longitudinal heat conductivity $κ_{xx}$ at $T\rightarrow0$ is elusive due to a very complex magnetic field dependence of $κ_{xx}$. Here, we report very low temperature (below 1~K) thermal conductivity ($κ$) of another candidate Kitaev material, Na$_2$Co$_2$TeO$_6$. The application of a magnetic field along different principal axes of the crystal reveals a strong directional-dependent magnetic-field ($\bf B$) impact on $κ$. We show that no evidence for mobile quasiparticles except phonons can be concluded at any field from 0~T to the field polarized state. In particular, severely scattered phonon transport is observed across the $B-T$ phase diagram, which is attributed to prominent magnetic fluctuations. Cascades of phase transitions are uncovered for all $\bf B$ directions by probing the strength of magnetic fluctuations via a precise record of $κ$($B$). Our results thus rule out recent proposals for itinerant magnetic excitations in Na$_2$Co$_2$TeO$_6$, and emphasise the importance of discriminating true spin liquid transport properties from scattered phonons in candidate materials.
title Phonon thermal transport shaped by strong spin-phonon scattering in a Kitaev material Na$_2$Co$_2$TeO$_6$
topic Strongly Correlated Electrons
Materials Science
url https://arxiv.org/abs/2306.16963