Du Lingjie, Knez Ivan, Sullivan Gerard, Du Rui-Rui
Department of Physics and Astronomy, Rice University, Houston, Texas 77251-1892, USA.
IBM Research-Almaden, San Jose, California 95120, USA.
Phys Rev Lett. 2015 Mar 6;114(9):096802. doi: 10.1103/PhysRevLett.114.096802. Epub 2015 Mar 4.
We have engineered electron-hole bilayers of inverted InAs/GaSb quantum wells, using dilute silicon impurity doping to suppress residual bulk conductance. We have observed robust helical edge states with wide conductance plateaus precisely quantized to 2e^{2}/h in mesoscopic Hall samples. On the other hand, in larger samples the edge conductance is found to be inversely proportional to the edge length. These characteristics persist in a wide temperature range and show essentially no temperature dependence. The quantized plateaus persist to a 12 T applied in-plane field; the conductance increases from 2e^{2}/h in strong perpendicular fields manifesting chiral edge transport. Our study presents a compelling case for exotic properties of a one-dimensional helical liquid on the edge of InAs/GaSb bilayers.
我们通过稀硅杂质掺杂抑制残余体电导，构建了InAs/GaSb量子阱倒置的电子 - 空穴双层结构。我们在介观霍尔样品中观测到了稳健的螺旋边缘态，其具有精确量子化为(2e^{2}/h)的宽电导平台。另一方面，在更大尺寸的样品中，边缘电导与边缘长度成反比。这些特性在很宽的温度范围内持续存在，且基本不依赖于温度。量子化平台在高达12 T的面内磁场下依然存在；在强垂直磁场中，电导从(2e^{2}/h)开始增加，表现出手征边缘输运。我们的研究为InAs/GaSb双层结构边缘一维螺旋液体的奇异特性提供了有力证据。
