论文标题
从WTE $ _2 $表面状态的光发射图中的几何诱导的自旋过滤
Geometry-induced spin-filtering in photoemission maps from WTe$_2$ surface states
论文作者
论文摘要
我们证明，重要的量子材料WTE $ _2 $在光发射中表现出一种新型的几何形状引起的自旋过滤效果，这是由于低对称性的造成了其异国情调的传输性能。通过激光驱动的自旋偏置角度分辨光发射费米表面映射，我们展示了来自WTE $ _2 $的表面状态的电子的高度不对称的旋转纹理。这样的不对称性不存在于初始状态自旋纹理中，这些态纹理受时间反转和晶格镜面对称性的结合。这些发现是通过一步模型光发射形式主义中理论模型定性地重现的。可以在自由电子最终状态模型中理解该效果是由于来自不同原子位点的发射而引起的干扰。观察到的效果是光发射过程中初始状态的时间交流对称性破坏的表现，因此不能消除它，而只能受到特殊实验几何形状的影响。
We demonstrate that an important quantum material WTe$_2$ exhibits a new type of geometry-induced spin-filtering effect in photoemission, stemming from low symmetry that is responsible for its exotic transport properties. Through the laser-driven spin-polarized angle-resolved photoemission Fermi surface mapping, we showcase highly asymmetric spin textures of electrons photoemitted from the surface states of WTe$_2$. Such asymmetries are not present in the initial state spin textures, which are bound by the time-reversal and crystal lattice mirror plane symmetries. The findings are reproduced qualitatively by theoretical modeling within the one-step model photoemission formalism. The effect could be understood within the free-electron final state model as an interference due to emission from different atomic sites. The observed effect is a manifestation of time-reversal symmetry breaking of the initial state in the photoemission process, and as such it cannot be eliminated, but only its magnitude influenced, by special experimental geometries.
