Origin of $A$-type antiferromagnetism and chiral split magnons in altermagnetic $α$-MnTe

Fuente: arXiv
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Main Authors: Alaei, Mojtaba, Sobieszczyk, Pawel, Ptok, Andrzej, Rezaei, Nafise, Oganov, Artem R., Qaiumzadeh, Alireza
Format: Preprint
Published: 2024
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author Alaei, Mojtaba
Sobieszczyk, Pawel
Ptok, Andrzej
Rezaei, Nafise
Oganov, Artem R.
Qaiumzadeh, Alireza
author_facet Alaei, Mojtaba
Sobieszczyk, Pawel
Ptok, Andrzej
Rezaei, Nafise
Oganov, Artem R.
Qaiumzadeh, Alireza
contents The origin of the $A$-type antiferromagnetic ordering, characterized by ferromagnetic layers coupling antiferromagnetically, in the prototype semiconductor altermagnet $α$-MnTe has been a topic of ongoing debate. Experimentally, $α$-MnTe exhibits an in-plane ferromagnetic exchange interaction, whereas previous \emph{ab initio} calculations predicted an antiferromagnetic interaction. In this paper, we resolve this discrepancy by considering an expanded set of magnetic configurations, which reveals a ferromagnetic in-plane exchange interaction in agreement with experimental findings. Additionally, we demonstrate that the 10th nearest-neighbor exchange interaction is directionally dependent, inducing a nonrelativistic chiral splitting in the magnon bands, as recently observed experimentally. We further show that applying a compressive strain may significantly enhance both nonrelativistic spin and chiral magnon splittings. The strain can also change the sign of the in-plane exchange interaction. Computing magnetic susceptibility, we show that strain enhances the N{é}el temperature, significantly. Our results highlight the critical importance of convergence in the number of magnetic configurations for spin interactions in antiferromagnetic materials.
format Preprint
id arxiv_https___arxiv_org_abs_2411_11985
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Origin of $A$-type antiferromagnetism and chiral split magnons in altermagnetic $α$-MnTe
Alaei, Mojtaba
Sobieszczyk, Pawel
Ptok, Andrzej
Rezaei, Nafise
Oganov, Artem R.
Qaiumzadeh, Alireza
Materials Science
Mesoscale and Nanoscale Physics
The origin of the $A$-type antiferromagnetic ordering, characterized by ferromagnetic layers coupling antiferromagnetically, in the prototype semiconductor altermagnet $α$-MnTe has been a topic of ongoing debate. Experimentally, $α$-MnTe exhibits an in-plane ferromagnetic exchange interaction, whereas previous \emph{ab initio} calculations predicted an antiferromagnetic interaction. In this paper, we resolve this discrepancy by considering an expanded set of magnetic configurations, which reveals a ferromagnetic in-plane exchange interaction in agreement with experimental findings. Additionally, we demonstrate that the 10th nearest-neighbor exchange interaction is directionally dependent, inducing a nonrelativistic chiral splitting in the magnon bands, as recently observed experimentally. We further show that applying a compressive strain may significantly enhance both nonrelativistic spin and chiral magnon splittings. The strain can also change the sign of the in-plane exchange interaction. Computing magnetic susceptibility, we show that strain enhances the N{é}el temperature, significantly. Our results highlight the critical importance of convergence in the number of magnetic configurations for spin interactions in antiferromagnetic materials.
title Origin of $A$-type antiferromagnetism and chiral split magnons in altermagnetic $α$-MnTe
topic Materials Science
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2411.11985