{"title":"Strain-explorable valley-polarized topological phase transition and perpendicular magnetocrystalline anisotropy in hexagonal MClBr (M = Ru, Os) monolayers","authors":"Zeyu Zhang, He Huang, Liming Wang, Yanzhe Zhao, Chuang Liu, Shiming Zhou, Yanfei Wu, Jiapeng Zhao, Guanxiong Qiao, Dingsong Wang, Jingyan Zhang, Xinqi Zheng, Shouguo Wang","doi":"10.1103/physrevb.110.035128","DOIUrl":null,"url":null,"abstract":"The coexistence of ferrovalley and band topology has garnered significant attention, due to its valley-polarized quantum anomalous Hall effect in condensed matter physics for two-dimensional (2D) ferromagnetic materials, in which the spontaneous out-of-plane magnetization and strong spin-orbit coupling effect are both satisfied. Here, using first-principles calculations and a tight-binding model, we reported the valley-polarized band topological phase transition and perpendicular magnetocrystalline anisotropy in a series of 2D Janus magnetic transition metal dihalides <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>H</mi></mrow><mo>−</mo><mrow><mi>M</mi><mi>ClBr</mi></mrow></math> (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>M</mi></mrow></math> = Ru, Os) via strain manipulation. Due to both the inversion and time-reversal asymmetry, valley polarization could be spontaneously achieved in hexagonal RuClBr and hexagonal OsClBr monolayers, with considerable values of 247 and 150 meV, respectively, which exceed those of most reported 2D ferrovalley materials. By applying an external biaxial strain, it is noteworthy that the easy magnetization axis of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>H</mi></mrow></math>-RuClBr can be switched to the out-of-plane direction due to distinct spin channel interactions between the Ru <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>d</mi></math> orbitals. Moreover, transitions from the anomalous valley Hall effect to the nontrivial topological state in both <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>H</mi></mrow></math>-RuClBr and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>H</mi></mrow></math>-OsClBr are observed. Due to the spontaneous valley polarization, band topology phase transition, and perpendicular magnetocrystalline anisotropy, it is expected that 2D Janus magnetic transition metal dihalides expand the application for the interplay among valleytronics, spintronics, and band topology.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physical Review B","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1103/physrevb.110.035128","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Physics and Astronomy","Score":null,"Total":0}
引用次数: 0
Abstract
The coexistence of ferrovalley and band topology has garnered significant attention, due to its valley-polarized quantum anomalous Hall effect in condensed matter physics for two-dimensional (2D) ferromagnetic materials, in which the spontaneous out-of-plane magnetization and strong spin-orbit coupling effect are both satisfied. Here, using first-principles calculations and a tight-binding model, we reported the valley-polarized band topological phase transition and perpendicular magnetocrystalline anisotropy in a series of 2D Janus magnetic transition metal dihalides ( = Ru, Os) via strain manipulation. Due to both the inversion and time-reversal asymmetry, valley polarization could be spontaneously achieved in hexagonal RuClBr and hexagonal OsClBr monolayers, with considerable values of 247 and 150 meV, respectively, which exceed those of most reported 2D ferrovalley materials. By applying an external biaxial strain, it is noteworthy that the easy magnetization axis of -RuClBr can be switched to the out-of-plane direction due to distinct spin channel interactions between the Ru orbitals. Moreover, transitions from the anomalous valley Hall effect to the nontrivial topological state in both -RuClBr and -OsClBr are observed. Due to the spontaneous valley polarization, band topology phase transition, and perpendicular magnetocrystalline anisotropy, it is expected that 2D Janus magnetic transition metal dihalides expand the application for the interplay among valleytronics, spintronics, and band topology.
期刊介绍:
Physical Review B (PRB) is the world’s largest dedicated physics journal, publishing approximately 100 new, high-quality papers each week. The most highly cited journal in condensed matter physics, PRB provides outstanding depth and breadth of coverage, combined with unrivaled context and background for ongoing research by scientists worldwide.
PRB covers the full range of condensed matter, materials physics, and related subfields, including:
-Structure and phase transitions
-Ferroelectrics and multiferroics
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-Magnetism
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-Electronic structure, photonics, and metamaterials
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-Surfaces, nanoscience, and two-dimensional materials
-Topological states of matter