论文标题
山谷通过边缘状态泵送和二维半导体的非局部山谷大厅效应
Valley Pumping via Edge States and the Nonlocal Valley Hall Effect in Two-Dimensional Semiconductors
论文作者
论文摘要
最近的实验研究了双层石墨烯中非局部转运的温度和栅极电压依赖性，从而识别被认为与二维半导体的批量内部山谷大厅效应相关的特征。在这里，我们使用简单的微观紧密结合色带模型和现象学大量传输方程来强调样品边缘对非局部电压信号的影响。我们表明，非局部山谷大厅的响应对样品边缘处的电子结构细节敏感，并且当局部纵向电导率在样品边缘附近的局部纵向电导率时，它会增强。根据这些发现，我们讨论了最新的实验，并讨论了山谷大厅效应中二维样品边缘附近的山谷之间的电子泵送的紧密类比，以及由于三维拓扑半学分的手性异常而导致的山谷之间的散装泵。
Recent experiments have studied the temperature and gate voltage dependence of nonlocal transport in bilayer graphene, identifying features thought to be associated with the two-dimensional semiconductor's bulk intrinsic valley Hall effect. Here, we use both simple microscopic tight-binding ribbon models and phenomenological bulk transport equations to emphasize the impact of sample edges on the nonlocal voltage signals. We show that the nonlocal valley Hall response is sensitive to electronic structure details at the sample edges, and that it is enhanced when the local longitudinal conductivity is larger near the sample edges than in the bulk. We discuss recent experiments in light of these findings and also discuss the close analogy between electron pumping between valleys near two-dimensional sample edges in the valley Hall effect, and bulk pumping between valleys due to the chiral anomaly in three-dimensional topological semimetals.
