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arXiv 0908.0881cond-mat.mes-hall
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拓扑安德森绝缘体理论

Theory of the topological Anderson insulator

C. W. Groth, M. Wimmer, A. R. Akhmerov, J. Tworzydło, C. W. J. Beenakker

摘要:

我们提出了一个有效介质理论,解释了无序诱导过渡到一个阶段的量子化电导,发现在计算机模拟碲化汞量子阱。随机势和与p^2 sigma_z成比例的狄拉克哈密顿量的二次修正的结合,可以将普通的带绝缘体驱动成拓扑绝缘体(具有反向带隙)。我们计算了弱无序相边界的位置,并表明它对应于带边的交叉,而不是迁移率边缘。我们的机制形成的拓扑安德森绝缘体是通用的,并将适用于三维半导体与强自旋轨道耦合。

英文摘要:

We present an effective medium theory that explains the disorder-induced transition into a phase of quantized conductance, discovered in computer simulations of HgTe quantum wells. It is the combination of a random potential and quadratic corrections proportional to p^2 sigma_z to the Dirac Hamiltonian that can drive an ordinary band insulator into a topological insulator (having an inverted band gap). We calculate the location of the phase boundary at weak disorder and show that it corresponds to the crossing of a band edge rather than a mobility edge. Our mechanism for the formation of a topological Anderson insulator is generic, and would apply as well to three-dimensional semiconductors with strong spin-orbit coupling.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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