Tunable quantum spin Hall effect in double quantum wells
Tunable quantum spin Hall effect in double quantum wells
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DOI：
10.1103/physrevb.85.125309
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发表时间：
2011-07
影响因子：
3.7
通讯作者：
P. Michetti;J. C. Budich;E. Novik;P. Recher
中科院分区：
文献类型：
--
作者：
P. Michetti;J. C. Budich;E. Novik;P. Recher
拓扑绝缘体（TI）领域正在迅速发展。关于可能的应用，寻找具有容易控制的TI相的材料是一个关键问题。在具有反转带隙的碲化汞基量子威尔斯（QW）中，量子自旋霍尔效应的特征是由时间反转对称性保护的单对螺旋边缘模。我们分析了一般耦合的碲化汞双量子阱（DQW）的拓扑特性，并展示了如何在这样的系统中的TI相可以由层间偏置电压驱动，即使当各个层是非反转的。我们认为，该系统允许类似的（层）赝自旋为基础的物理在双层石墨烯，但与谷简并的关键情况下。
The field of topological insulators (TIs) is rapidly growing. Concerning possible applications, the search for materials with an easily controllable TI phase is a key issue. The quantum spin Hall effect, characterized by a single pair of helical edge modes protected by time-reversal symmetry, has been demonstrated in HgTe-based quantum wells (QWs) with an inverted bandgap. We analyze the topological properties of a generically coupled HgTe-based double QW (DQW) and show how in such a system a TI phase can be driven by an inter-layer bias voltage, even when the individual layers are non-inverted. We argue, that this system allows for similar (layer-)pseudospin based physics as in bilayer graphene but with the crucial absence of a valley degeneracy.