Impact of triplon damping on thermal Hall conductivity in Shastry-Sutherland model

Fuente: arXiv
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Autores principales: Koyama, Shinnosuke, Nasu, Joji
Formato: Preprint
Publicado: 2024
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author Koyama, Shinnosuke
Nasu, Joji
author_facet Koyama, Shinnosuke
Nasu, Joji
contents We investigate the thermal Hall effect in the Shastry-Sutherland model, incorporating interactions between quasiparticle excitations. In this model, with strong nearest-neighbor interactions, the ground state is well described by the direct product of spin-singlet states, and the elementary excitations to spin-triplet states are known as triplons. In candidate materials for this model, Dzyaloshinskii-Moriya interactions are inevitably present, resulting in topologically non-trivial band structures for triplon excitations. In this study, we examine quasiparticle damping due to triplon-triplon interactions as a potential factor contributing to the suppression of the thermal Hall effect. We apply nonlinear flavor-wave theory to the Shastry-Sutherland model and treat triplons as bosonic excitations. We calculate the triplon damping rate using the imaginary Dyson equation approach and evaluate the thermal Hall conductivity. Our findings demonstrate that triplons with nonzero Berry curvature are scattered by thermally excited triplons. This scattering effect suppresses the thermal Hall conductivity, particularly at finite temperatures, highlighting the significant role of triplon damping in the thermal Hall effect.
format Preprint
id arxiv_https___arxiv_org_abs_2411_10065
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Impact of triplon damping on thermal Hall conductivity in Shastry-Sutherland model
Koyama, Shinnosuke
Nasu, Joji
Strongly Correlated Electrons
Materials Science
We investigate the thermal Hall effect in the Shastry-Sutherland model, incorporating interactions between quasiparticle excitations. In this model, with strong nearest-neighbor interactions, the ground state is well described by the direct product of spin-singlet states, and the elementary excitations to spin-triplet states are known as triplons. In candidate materials for this model, Dzyaloshinskii-Moriya interactions are inevitably present, resulting in topologically non-trivial band structures for triplon excitations. In this study, we examine quasiparticle damping due to triplon-triplon interactions as a potential factor contributing to the suppression of the thermal Hall effect. We apply nonlinear flavor-wave theory to the Shastry-Sutherland model and treat triplons as bosonic excitations. We calculate the triplon damping rate using the imaginary Dyson equation approach and evaluate the thermal Hall conductivity. Our findings demonstrate that triplons with nonzero Berry curvature are scattered by thermally excited triplons. This scattering effect suppresses the thermal Hall conductivity, particularly at finite temperatures, highlighting the significant role of triplon damping in the thermal Hall effect.
title Impact of triplon damping on thermal Hall conductivity in Shastry-Sutherland model
topic Strongly Correlated Electrons
Materials Science
url https://arxiv.org/abs/2411.10065