Surface states and arcless angles in twisted Weyl semimetals
Surface states and arcless angles in twisted Weyl semimetals
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DOI：
10.1103/physrevresearch.2.013367
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发表时间：
2019-09
影响因子：
4.2
通讯作者：
G. Murthy;H. Fertig;E. Shimshoni
中科院分区：
文献类型：
--
作者：
G. Murthy;H. Fertig;E. Shimshoni
费米弧态是Weyl半金属（WSM）表面的特征，由于其体带结构的拓扑特性而具有很强的鲁棒性。我们证明了当具有明确定义的扭转角的不同系统的表面是隧道耦合时，费米弧可能发生深刻的重构。扭曲的WSM接口支持一个可以近似为具有大实空间单元胞的周期系统的莫尔模式。结合在界面上的状态出现了，当垂直于系统表面施加磁场时，预期的磁振荡产生了有趣的结果。当扭转角经过特殊的“无弧角”时，在界面上不存在开放的费米弧态，限制在界面上的态的费米环可能会断开，而不会连接到WSM的体态。我们认为，在垂直于界面的磁场中，这种状态在系统的光学电导率中具有有趣的共振特征。
Fermi arc states are features of Weyl semimetal (WSM) surfaces which are robust due to the topological character of the bulk band structure. We demonstrate that Fermi arcs may undergo profound restructurings when surfaces of different systems with a well-defined twist angle are tunnel-coupled. The twisted WSM interface supports a moir\'e pattern which may be approximated as a periodic system with large real-space unit cell. States bound to the interface emerge, with interesting consequences for the magneto-oscillations expected when a magnetic field is applied perpendicular to the system surfaces. As the twist angle passes through special "arcless angles', for which open Fermi arc states are absent at the interface, Fermi loops of states confined to the interface may break off, without connecting to bulk states of the WSM. We argue that such states have interesting resonance signatures in the optical conductivity of the system in a magnetic field perpendicular to the interface.