Localization of trivial edge states in InAs/GaSb composite quantum wells
Localization of trivial edge states in InAs/GaSb composite quantum wells
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DOI：
10.1103/physrevb.100.041404
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发表时间：
2019-07-17
影响因子：
3.7
通讯作者：
Kaya, Ismet I.
中科院分区：
文献类型：
--
作者：
Sazgari, Vahid;Sullivan, Gerard;Kaya, Ismet I.
InAs/GaSb异质结构是预计会出现量子自旋霍尔效应的系统之一。然而，正如最近的实验研究所证实的那样，该效应最显着的亮点，即由非平凡边缘态引起的电导量子化，被由平凡边缘态产生的杂散电导率所掩盖。在这篇《快速通讯》中，我们对 InAs/GaSb 异质结构中平凡边缘模式的强局域化进行了实验观察，该异质结构被 InAs 层内的硅三角掺杂剂弱无序化。边缘传导的特点是在低温下具有与温度无关的行为，在高温下具有幂律，据观察，边缘传导随边缘长度呈指数变化。对一系列设备测量的综合分析与准一维电子系统中的局域化理论一致。
The InAs/GaSb heterostructure is one of the systems where the quantum spin Hall effect is predicted to arise. However, as confirmed by recent experimental studies, the most significant highlight of the effect, i.e., conductance quantization due to nontrivial edge states, is obscured by spurious conductivity arising from trivial edge states. In this Rapid Communication, we present an experimental observation of the strong localization of trivial edge modes in an InAs/GaSb heterostructure which was weakly disordered by silicon deltalike dopants within the InAs layer. The edge conduction which is characterized by a temperature-independent behavior at low temperatures and a power law at high temperatures is observed to be exponentially scaled with the length of the edge. Comprehensive analyses on measurements with a range of devices is in agreement with the localization theories in quasi-one-dimensional electronic systems.