Conversion of chiral phonons into magnons in ferromagnets and antiferromagnets

Fuente: arXiv
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Main Authors: Yao, Dapeng, Murakami, Shuichi
Format: Preprint
Published: 2023
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author Yao, Dapeng
Murakami, Shuichi
author_facet Yao, Dapeng
Murakami, Shuichi
contents Chiral phonons with atomic rotations converted into electron spins result in a change of spin magnetizations in crystals. In this paper, we investigate a new conversion of chiral phonons into magnons both in ferromagnets and antiferromagnets by spin models with exchange and Dzyaloshinskii-Moriya interactions. The atomic rotations in chiral phonons are treated as slow phonons, which modulate spin-spin interaction and induce time-dependent magnon excitations due to geometric effect within adiabatic approximation. We demonstrate that a non-trivial change of the number of magnons requires breaking of the spin-rotation symmetry around the spin quantization axis. As a result, the clockwise and counterclockwise chiral phonons induce a change of the magnon number with opposite signs, which corresponds to an increasing or decreasing spin magnetizaton due to the chiral nature of the atomic rotations. In particular, in antiferromagnets, the modulation of magnons due to chiral phonons generates a non-zero net magnetization by the proposed effect, which is expect to be observed in experiments.
format Preprint
id arxiv_https___arxiv_org_abs_2304_14000
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Conversion of chiral phonons into magnons in ferromagnets and antiferromagnets
Yao, Dapeng
Murakami, Shuichi
Mesoscale and Nanoscale Physics
Chiral phonons with atomic rotations converted into electron spins result in a change of spin magnetizations in crystals. In this paper, we investigate a new conversion of chiral phonons into magnons both in ferromagnets and antiferromagnets by spin models with exchange and Dzyaloshinskii-Moriya interactions. The atomic rotations in chiral phonons are treated as slow phonons, which modulate spin-spin interaction and induce time-dependent magnon excitations due to geometric effect within adiabatic approximation. We demonstrate that a non-trivial change of the number of magnons requires breaking of the spin-rotation symmetry around the spin quantization axis. As a result, the clockwise and counterclockwise chiral phonons induce a change of the magnon number with opposite signs, which corresponds to an increasing or decreasing spin magnetizaton due to the chiral nature of the atomic rotations. In particular, in antiferromagnets, the modulation of magnons due to chiral phonons generates a non-zero net magnetization by the proposed effect, which is expect to be observed in experiments.
title Conversion of chiral phonons into magnons in ferromagnets and antiferromagnets
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2304.14000