Pan Hui, Li Zhenshan, Liu Cheng-Cheng, Zhu Guobao, Qiao Zhenhua, Yao Yugui
Department of Physics, Beihang University, Beijing 100191, China.
School of Physics, Beijing Institute of Technology, Beijing 100081, China.
Phys Rev Lett. 2014 Mar 14;112(10):106802. doi: 10.1103/PhysRevLett.112.106802. Epub 2014 Mar 12.
We find theoretically a new quantum state of matter-the valley-polarized quantum anomalous Hall state in silicene. In the presence of Rashba spin-orbit coupling and an exchange field, silicene hosts a quantum anomalous Hall state with Chern number C=2. We show that through tuning the Rashba spin-orbit coupling, a topological phase transition results in a valley-polarized quantum anomalous Hall state, i.e., a quantum state that exhibits the electronic properties of both the quantum valley Hall state (valley Chern number Cv=3) and quantum anomalous Hall state with C=-1. This finding provides a platform for designing dissipationless valleytronics in a more robust manner.
我们从理论上发现了一种新的物质量子态——硅烯中的谷极化量子反常霍尔态。在存在Rashba自旋轨道耦合和交换场的情况下，硅烯拥有一个陈数C = 2的量子反常霍尔态。我们表明，通过调节Rashba自旋轨道耦合，一个拓扑相变会导致一个谷极化量子反常霍尔态，即一种展现出量子谷霍尔态（谷陈数Cv = 3）和C = -1的量子反常霍尔态两者电子性质的量子态。这一发现为以更稳健的方式设计无耗散谷电子学提供了一个平台。
