Spin-Selective Second-Order Topological Insulators Enabling Cornertronics in 2D Altermagnets

Fuente: arXiv
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Main Authors: Yang, Ning-Jing, Huang, Zhigao, Zhang, Jian-Min
Format: Preprint
Published: 2025
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author Yang, Ning-Jing
Huang, Zhigao
Zhang, Jian-Min
author_facet Yang, Ning-Jing
Huang, Zhigao
Zhang, Jian-Min
contents Recent progress in spintronics within the paradigm of altermagnets (AMs) opens new avenues for next-generation electronic device design. Here, we establish a spin-corner locking mechanism that generates second-order topological states in two-dimensional (2D) altermagnetic systems, through effective model analysis. Remarkably, the breaking of Mxy symmetry under uniaxial strain creates spin-resolved corner modes, driving the system into a corner-polarized second-order topological insulator (CPSOTI). Beyond critical strain, a topological phase transition to quantum anomalous Hall insulator occurs with quantized conductance. Through first-principles calculations, we identify two experimentally viable candidates for 2D intrinsic AM CrO and Cr$_2$Se$_2$O -- which host robust CPSOTI. Moreover, we construct the topological phase diagram of CrO and predict the existence of an altermagnetic Weyl semimetal phase. Our findings open technological avenues in altermagnetism and higher-order topology, while providing opportunities for coupling topological spintronics with cornertronics.
format Preprint
id arxiv_https___arxiv_org_abs_2510_13319
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Spin-Selective Second-Order Topological Insulators Enabling Cornertronics in 2D Altermagnets
Yang, Ning-Jing
Huang, Zhigao
Zhang, Jian-Min
Mesoscale and Nanoscale Physics
Materials Science
Recent progress in spintronics within the paradigm of altermagnets (AMs) opens new avenues for next-generation electronic device design. Here, we establish a spin-corner locking mechanism that generates second-order topological states in two-dimensional (2D) altermagnetic systems, through effective model analysis. Remarkably, the breaking of Mxy symmetry under uniaxial strain creates spin-resolved corner modes, driving the system into a corner-polarized second-order topological insulator (CPSOTI). Beyond critical strain, a topological phase transition to quantum anomalous Hall insulator occurs with quantized conductance. Through first-principles calculations, we identify two experimentally viable candidates for 2D intrinsic AM CrO and Cr$_2$Se$_2$O -- which host robust CPSOTI. Moreover, we construct the topological phase diagram of CrO and predict the existence of an altermagnetic Weyl semimetal phase. Our findings open technological avenues in altermagnetism and higher-order topology, while providing opportunities for coupling topological spintronics with cornertronics.
title Spin-Selective Second-Order Topological Insulators Enabling Cornertronics in 2D Altermagnets
topic Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2510.13319