Murakami Shuichi, Nagaosa Naoto, Zhang Shou-Cheng
Department of Applied Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Phys Rev Lett. 2004 Oct 8;93(15):156804. doi: 10.1103/PhysRevLett.93.156804. Epub 2004 Oct 6.
Recent theories predict dissipationless spin current induced by an electric field in doped semiconductors. Nevertheless, the charge current is still dissipative in these systems. In this work, we theoretically predict the dissipationless spin-Hall effect, without any accompanying charge current, in some classes of band insulators, including zero-gap semiconductors such as HgTe and narrow-gap semiconductors such as PbTe. This effect is similar to the quantum-Hall effect in that all the states below the gap contribute and there occurs no dissipation. However, the spin-Hall conductance is not quantized even in two dimensions. This is the first example of a nontrivial topological structure in a band insulator without any magnetic field.
近期理论预测，在掺杂半导体中，电场可诱导出无耗散的自旋电流。然而，在这些系统中，电荷电流仍然是有耗散的。在本工作中，我们从理论上预测了在某些类别的带绝缘体中，包括诸如HgTe这样的零带隙半导体和诸如PbTe这样的窄带隙半导体，存在无伴随电荷电流的无耗散自旋霍尔效应。该效应与量子霍尔效应相似，即带隙以下的所有态都有贡献且不发生耗散。然而，即使在二维情况下，自旋霍尔电导也不是量子化的。这是在没有任何磁场的带绝缘体中出现非平凡拓扑结构的首个例子。
