Lin Shi-Qing, Tan Hui, Fu Pei-Hao, Liu Jun-Feng
School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, China.
Science, Mathematics and Technology, Singapore University of Technology and Design, 8 Somapah Road, Singapore City 487372, Singapore.
iScience. 2023 Aug 7;26(9):107546. doi: 10.1016/j.isci.2023.107546. eCollection 2023 Sep 15.
The magnetic interaction is a necessary ingredient to break the time-reversal symmetry in realizing quantum anomalous Hall, or Chern insulating phases. Here, we study topological phases in the model, a minimal theoretical model supporting the flat band, taking account of Rashba spin-orbit coupling and flat-band-induced spontaneous ferromagnetism. By analyzing the interaction-driven phase diagrams, band structures, topological edge states, and topological invariants, we demonstrate that this system offers a platform for realizing a wide range of phases, including normal insulators, semimetals, and Chern insulators. Uniquely, there exist both high-Chern-number insulators and valley-polarized Chern insulators. In the latter phase, edge channels exist in the single valley, leading to nearly valley polarization. These findings demonstrate the potential of interaction-driven systems in realizing exotic phases and their promising role in future applications in topology electronics and valleytronics.
磁相互作用是在实现量子反常霍尔或陈绝缘相时打破时间反演对称性的必要因素。在此，我们研究了模型中的拓扑相，该模型是支持平带的最小理论模型，考虑了 Rashba 自旋轨道耦合和平带诱导的自发铁磁性。通过分析相互作用驱动的相图、能带结构、拓扑边缘态和拓扑不变量，我们证明该系统为实现包括正常绝缘体、半金属和陈绝缘体在内的广泛相提供了一个平台。独特的是，既存在高陈数绝缘体，也存在谷极化陈绝缘体。在后一种相中，单谷中存在边缘通道，导致近乎谷极化。这些发现证明了相互作用驱动系统在实现奇异相方面的潜力及其在拓扑电子学和谷电子学未来应用中的前景。
