Strain-Induced Antiferromagnetic-to-Altermagnetic Phase Transition and Topology in $(\mathrm{CrO}_2)_1/(\mathrm{TaO}_2)_2$ Superlattice

Fuente: arXiv
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Main Authors: Shan, Wanfei, Yang, Qun, Narang, Prineha
Format: Preprint
Published: 2025
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author Shan, Wanfei
Yang, Qun
Narang, Prineha
author_facet Shan, Wanfei
Yang, Qun
Narang, Prineha
contents Topological aspects in altermagnets have come into focus recently, and tuning the antiferromagnetic (AFM) state into an altermagnetic phase remains an active frontier. We realize both within a rutile superlattice here in this paper. With first principles calculation, we show that a uniaxial strain of only 0.5$\%$ along the c axis converts the $(\mathrm{CrO}_2)_1/(\mathrm{TaO}_2)_2$ rutile superlattice from a trivial antiferromagnet into an altermagnet with topology accompanied by a weak SOC. The strain opens a spin-dependent band splitting of $\sim 1.1 eV$ and, despite the weak SOC together with in-plane magnetic moment orientation, generates an intrinsic anomalous Hall conductivity of order $10^3 S/cm$, comparable magnitude to that in ferromagnetic Weyl semimetals. Tiny SOC here with in-plane \(\text{Néel}\) orientation gaps out the Weyl nodal rings, giving rise to 16 Weyl points in the superlattice. Thus, we point out a simple route toward strain and field tunable, low-dissipation altermagnetic electronics.
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publishDate 2025
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spellingShingle Strain-Induced Antiferromagnetic-to-Altermagnetic Phase Transition and Topology in $(\mathrm{CrO}_2)_1/(\mathrm{TaO}_2)_2$ Superlattice
Shan, Wanfei
Yang, Qun
Narang, Prineha
Materials Science
Topological aspects in altermagnets have come into focus recently, and tuning the antiferromagnetic (AFM) state into an altermagnetic phase remains an active frontier. We realize both within a rutile superlattice here in this paper. With first principles calculation, we show that a uniaxial strain of only 0.5$\%$ along the c axis converts the $(\mathrm{CrO}_2)_1/(\mathrm{TaO}_2)_2$ rutile superlattice from a trivial antiferromagnet into an altermagnet with topology accompanied by a weak SOC. The strain opens a spin-dependent band splitting of $\sim 1.1 eV$ and, despite the weak SOC together with in-plane magnetic moment orientation, generates an intrinsic anomalous Hall conductivity of order $10^3 S/cm$, comparable magnitude to that in ferromagnetic Weyl semimetals. Tiny SOC here with in-plane \(\text{Néel}\) orientation gaps out the Weyl nodal rings, giving rise to 16 Weyl points in the superlattice. Thus, we point out a simple route toward strain and field tunable, low-dissipation altermagnetic electronics.
title Strain-Induced Antiferromagnetic-to-Altermagnetic Phase Transition and Topology in $(\mathrm{CrO}_2)_1/(\mathrm{TaO}_2)_2$ Superlattice
topic Materials Science
url https://arxiv.org/abs/2509.21741