Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA.
Nanoscale. 2018 Aug 23;10(33):15462-15467. doi: 10.1039/c8nr04878a.
To explore new methods for the realization of the quantum spin Hall (QSH) effect in two-dimensional (2D) materials, we have constructed a honeycomb geometry (HG) by etching rows of hexagonal holes in HgTe quantum wells (QWs). Theoretical calculations show that multiple Dirac cones can be produced by HG, regardless of whether the band inversion occurs or not. Furthermore, the topological states originating from a narrow HG region in a wide ribbon show strong localization at the physical edges of the ribbon, making them easy to manipulate and exploit. When the band inversion condition for QW states is satisfied, the topological states generated by two different mechanisms may coexist. Our studies pave the way to produce and control multiple QSH states in 2D materials as desired for the design of innovative spintronic materials.
为了探索在二维（2D）材料中实现量子自旋霍尔（QSH）效应的新方法，我们通过在 HgTe 量子阱（QW）中刻蚀六边形孔的行来构建了一个蜂窝状结构（HG）。理论计算表明，无论带反转是否发生，HG 都可以产生多个狄拉克锥。此外，起源于宽带状物中狭窄 HG 区域的拓扑状态在带状物的物理边缘处表现出强烈的局域性，使其易于操纵和利用。当满足 QW 状态的带反转条件时，两种不同机制产生的拓扑状态可能共存。我们的研究为在 2D 材料中产生和控制多个 QSH 状态铺平了道路，这是设计创新的自旋电子材料的关键。
