Topological insulator: a new quantized spin Hall resistance robust to dephasing

The influence of dephasing on the quantum spin Hall effect (QSHE) is studied. In the absence of dephasing, the longitudinal resistance in a QSHE system exhibits the quantum plateaus. We find that these quantum plateaus are robust against the normal dephasing but fragile with the spin dephasing. Thus...

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Bibliographic Details
Published in:arXiv.org 2008-11
Main Authors: Jiang, Hua, Cheng, Shuguang, Qing-feng, Sun, Xie, X C
Format: Article
Language:English
Subjects:
Quantum Hall effect
Robustness
Topological insulators
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Summary:The influence of dephasing on the quantum spin Hall effect (QSHE) is studied. In the absence of dephasing, the longitudinal resistance in a QSHE system exhibits the quantum plateaus. We find that these quantum plateaus are robust against the normal dephasing but fragile with the spin dephasing. Thus, these quantum plateaus only survive in mesoscopic samples. Moreover, the longitudinal resistance increases linearly with the sample length but is insensitive to the sample width. These characters are in excellent agreement with the recent experimental results [science {\bf 318}, 766 (2007)]. In addition, we define a new spin Hall resistance that also exhibits quantum plateaus. In particular, these plateaus are robust against any type of dephasing and therefore, survive in macroscopic samples and better reflect the topological nature of QSHE.
ISSN:2331-8422
DOI:10.48550/arxiv.0811.1610