Floquet valley-polarized quantum anomalous hall state in nonmagnetic heterobilayers

作     者：Zhan, Fangyang Ning, Zhen Gan, Li-Yong Zheng, Baobing Fan, Jing Wang, Rui 

作者机构：Institute for Structure and Function Department of Physics Chongqing University Chongqing400044 China Chongqing Key Laboratory for Strongly Coupled Physics Chongqing400044 China Center for Computational Science and Engineering Southern University of Science and Technology Shenzhen518055 China Center for Quantum Materials and Devices Chongqing University Chongqing400044 China College of Physics and Optoelectronic Technology Baoji University of Arts and Sciences Baoji721016 China 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2021年

核心收录：

主　　题：Landforms 

摘      要：The valley-polarized quantum anomalous Hall (VQAH) state, which forwards a strategy for combining valleytronics and spintronics with nontrivial topology, attracts intensive interest in condensedmatter physics. So far, the explored VQAH states have still been limited to magnetic systems. Here, using the low-energy effective model and Floquet theorem, we propose a different mechanism to realize the Floquet VQAH state in nonmagnetic heterobilayers under light irradiation. We then realize this proposal via first-principles calculations in transition metal dichalcogenide heterobilayers, which initially possess the time-reversal invariant valley quantum spin Hall (VQSH) state. By irradiating circularly polarized light, the time-reversal invariant VQSH state can evolve into the VQAH state, behaving as an optically switchable topological spin-valley filter. These findings not only offer a rational scheme to realize the VQAH state without magnetic orders, but also pave a fascinating path for designing topological spintronic and valleytronic devices. Copyright © 2021, The Authors. All rights reserved.