Topological magnons in a non-coplanar magnetic order on the triangular lattice

Fuente: arXiv
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Main Authors: Bai, Linli, Chen, Ken
Format: Preprint
Published: 2024
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_version_ 1866909214320885760
author Bai, Linli
Chen, Ken
author_facet Bai, Linli
Chen, Ken
contents The bond-dependent Kitaev interaction $K$ is familiar in the effective spin model of transition metal compounds with octahedral ligands. In this work, we find a peculiar non-coplanar magnetic order can be formed with the help of $K$ and next-nearest neighbor Heisenberg coupling $J_2$ on the triangular lattice. It can be seen as a miniature version of skyrmion crystal, since it has nine spins and an integer topological number in a magnetic unit cell. The magnon excitations in such an order are studied by the linear spin-wave theory. Of note is that the change in the relative size of $J_2$ and $K$ produces topological magnon phase transitions although the topological number remains unchanged. We also calculated the experimentally observable thermal Hall conductivity, and found that the signs of thermal Hall conductivity will change with topological phase transitions or temperature changes in certain regions.
format Preprint
id arxiv_https___arxiv_org_abs_2401_12505
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Topological magnons in a non-coplanar magnetic order on the triangular lattice
Bai, Linli
Chen, Ken
Strongly Correlated Electrons
Materials Science
Other Condensed Matter
The bond-dependent Kitaev interaction $K$ is familiar in the effective spin model of transition metal compounds with octahedral ligands. In this work, we find a peculiar non-coplanar magnetic order can be formed with the help of $K$ and next-nearest neighbor Heisenberg coupling $J_2$ on the triangular lattice. It can be seen as a miniature version of skyrmion crystal, since it has nine spins and an integer topological number in a magnetic unit cell. The magnon excitations in such an order are studied by the linear spin-wave theory. Of note is that the change in the relative size of $J_2$ and $K$ produces topological magnon phase transitions although the topological number remains unchanged. We also calculated the experimentally observable thermal Hall conductivity, and found that the signs of thermal Hall conductivity will change with topological phase transitions or temperature changes in certain regions.
title Topological magnons in a non-coplanar magnetic order on the triangular lattice
topic Strongly Correlated Electrons
Materials Science
Other Condensed Matter
url https://arxiv.org/abs/2401.12505