Department of Physics, University of Gothenburg, SE 412 96 Gothenburg, Sweden.
Phys Rev Lett. 2010 Jun 25;104(25):256804. doi: 10.1103/PhysRevLett.104.256804. Epub 2010 Jun 24.
We analyze the dynamics of the helical edge modes of a quantum spin Hall state in the presence of a spatially nonuniform Rashba spin-orbit (SO) interaction. A randomly fluctuating Rashba SO coupling is found to open a scattering channel which causes localization of the edge modes for a weakly screened electron-electron (e-e) interaction. A periodic modulation of the SO coupling, with a wave number commensurate with the Fermi momentum, makes the edge insulating already at intermediate strengths of the e-e interaction. We discuss implications for experiments on edge state transport in a HgTe quantum well.
我们分析了存在空间非均匀拉什巴自旋轨道（SO）相互作用时量子自旋霍尔态的螺旋边缘模式的动力学。随机涨落的拉什巴 SO 耦合会打开一个散射通道，从而导致在电子-电子（e-e）相互作用较弱的情况下边缘模式局域化。当 SO 耦合的调制波数与费米动量相同时，即使在 e-e 相互作用的中等强度下，也会使边缘绝缘。我们讨论了对 HgTe 量子阱中边缘态输运实验的影响。
