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arXiv 1401.7461cond-mat.mes-hallcond-mat.dis-nn
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三维无序拓扑绝缘体的Z2 phase diagram的散射矩阵方法

Z2 phase diagram of three-dimensional disordered topological insulator via scattering matrix approach

Björn Sbierski, Piet W. Brouwer

摘要:

无序在三维时反不变性拓扑绝缘体中的作用是近年来的一个研究热点。然而,大型无序系统的Z2不变量的计算仍然是一个相当大的挑战。在本文中,我们应用和扩展最近提出的方法的基础上的散射矩阵的方法,它允许在合理的计算工作量与几个通道的引线的大型系统的研究。通过直接计算Z2不变量的无序拓扑安德森绝缘体,我们明确地确定了这个阶段的拓扑性质,而不诉诸于它的连接与清洁的情况下。我们能够有效地计算在质量无序平面的Z2相图。拓扑相边界被发现是很好地描述了自洽玻恩近似,无论是为零和有限的化学势。

英文摘要:

The role of disorder in the field of three-dimensional time reversal invariant topological insulators has become an active field of research recently. However, the computation of Z2 invariants for large, disordered systems still poses a considerable challenge. In this paper we apply and extend a recently proposed method based on the scattering matrix approach, which allows the study of large systems at reasonable computational effort with few-channel leads. By computing the Z2 invariant directly for the disordered topological Anderson insulator, we unambiguously identify the topological nature of this phase without resorting to its connection with the clean case. We are able to efficiently compute the Z2 phase diagram in the mass-disorder plane. The topological phase boundaries are found to be well described by the self consistent Born approximation, both for vanishing and finite chemical potential.

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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