Affiliation:
1. School of Physics and Electronics, Shandong Normal University 1 , Jinan 250358, China
2. Shandong Provincial Engineering and Technical Center of Light Manipulations & Institute of Materials and Clean Energy, Shandong Normal University 2 , Jinan 250358, China
Abstract
The combination of valleytronics and topology has great potential significance in condensed matter and material physics. Here, based on first-principles calculations, we predict a dipolar ferromagnetic semiconductor OsClBr. Benefiting from strong spin–orbit coupling and the intrinsic exchange interaction of localized d electrons, spontaneous valley polarization occurs. In addition, the tensile strain can induce topological phase transitions between ferrovalley, half-valley-metal, and valley-polarization quantum anomalous Hall (VQAH) phases, which can be attributed to the band inversion between dz2 and dxy/dx2−y2 orbitals of Os atom. Moreover, stacking-dependent topological phase transitions can be found in bilayer OsClBr, and the robustness of VQAH phase in b − 1 configuration under a wide strain range has been proved, which is greatly beneficial for the regulation of quantum states. Our work provides a potential opportunity for the preparation and application of low-power consumption electronics devices.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Shandong Province
Qingchuang Science and Technology Plan of Shandong Province
Subject
Physics and Astronomy (miscellaneous)