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arXiv 0811.1610cond-mat.mes-hall
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拓扑绝缘体:一种新的对退相鲁棒的量子化自旋霍尔电阻

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

Hua Jiang, Shuguang Cheng, Qing-feng Sun, X. C. Xie

摘要:

研究了退相对量子自旋霍尔效应(QSHE)的影响。在没有退相的情况下,QSHE系统中的纵向电阻呈现量子平台。我们发现这些量子平台对正常的退相是稳健的,但与自旋退相脆弱。因此,这些量子平台只存在于介观样品中。此外,纵向电阻随样品长度线性增加,但对样品宽度不敏感。这些特征与最近的实验结果非常一致[science { \bf 318},766(2007)]。此外,我们定义了一个新的自旋霍尔电阻,也表现出量子平台。特别是,这些平台对任何类型的退相都是稳健的,因此,在宏观样品中存活,更好地反映了QSHE的拓扑性质。

英文摘要:

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.

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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