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arXiv 1402.7116cond-mat.dis-nn
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强无序下的AIII和BDI拓扑系统

AIII and BDI Topological Systems at Strong Disorder

Juntao Song, Emil Prodan

摘要:

使用一个明确的1维模型,我们提供了直接的证据表明,一维拓扑相位从AIII和BDI对称类遵循$\mathbb Z$分类,即使在强无序制度时,费米能级嵌入在一个密集的本地化的频谱。我们分析的主要工具是缠绕数$ν$,在I.作者:J. L. Hughes和E.普罗丹,arXiv:1311.5233。对于这两个类,通过改变模型的参数和/或无序强度,级联的尖锐的拓扑转变$ν=0 \rightarrow ν=1 \rightarrow ν=2$生成,在该制度中,绝缘间隙完全填充的本地化频谱。我们证明了每个拓扑转变都伴随着一个安德森局域化-离域转变。此外,为了明确排除$\mathbb Z_2$分类,生成$ν=0$和$ν=2$之间的拓扑转换。这两个阶段也被发现是分开的安德森局域化-离域过渡,从而证明他们的独特身份。

英文摘要:

Using an explicit 1-dimensional model, we provide direct evidence that the one-dimensional topological phases from the AIII and BDI symmetry classes follow a $\mathbb Z$-classification, even in the strong disorder regime when the Fermi level is embedded in a dense localized spectrum. The main tool for our analysis is the winding number $ν$, in the non-commutative formulation introduced in I. Mondragon-Shem, J. Song, T. L. Hughes, and E. Prodan, arXiv:1311.5233. For both classes, by varying the parameters of the model and/or the disorder strength, a cascade of sharp topological transitions $ν=0 \rightarrow ν=1 \rightarrow ν=2$ is generated, in the regime where the insulating gap is completely filled with the localized spectrum. We demonstrate that each topological transition is accompanied by an Anderson localization-delocalization transition. Furthermore, to explicitly rule out a $\mathbb Z_2$ classification, a topological transition between $ν=0$ and $ν=2$ is generated. These two phases are also found to be separated by an Anderson localization-delocalization transition, hence proving their distinct identity.

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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