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arXiv 1108.4483cond-mat.str-el
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拓扑绝缘体中分数量子霍尔态的特征

Signatures of Fractional Quantum Hall States in Topological Insulators

Dong-Xia Qu, Y. S. Hor, R. J. Cava

摘要:

分数量子霍尔(Fractional quantum Hall,缩写为HHH)态是一种由相互作用的电子的多体效应引起的物质拓扑状态,在基础物理学中有着广泛的研究兴趣。三维固体中拓扑表面态的实验观测使我们能够研究相关手征狄拉克费米子系统,该系统可以拥有一个没有自旋简并的狄拉克谷。最近的理论研究表明,在拓扑绝缘体中可以观察到分数量子霍尔效应。然而,由于占主导地位的体导电,这是很难探测的强关联效应拓扑绝缘体从电阻率测量。在这里,我们报告的Bi2Te3热电测量发现的BITOH状态。表面热电势是体热电势的10倍,这使得在SS中观察分数填充朗道能级成为可能。因此,热电势为研究拓扑绝缘体中的关联狄拉克费米子提供了一个强有力的工具。我们的观察表明,狄拉克拓扑SS在高磁场中表现出强关联相,并将使各种奇异的分数量子霍尔物理和其他相关现象的研究,在这个新发现的手征狄拉克系统。

英文摘要:

The fractional quantum Hall (FQH) state is a topological state of matter resulting from the many-body effect of interacting electrons and is of vast interest in fundamental physics. The experimental observation of topological surface states (SSs) in three-dimensional bulk solids has allowed the study of a correlated chiral Dirac fermion system, which can host a single Dirac valley without spin degeneracy. Recent theoretical studies suggest that the fractional quantum Hall effect (FQHE) might be observable in topological insulators. However, due to the dominant bulk conduction it is difficult to probe the strong correlation effect in topological insulators from resistivity measurements. Here we report the discovery of FQH states in Bi2Te3 from thermopower measurements. The surface thermopower is ten times greater than that of bulk, which makes possible the observation of fractional-filled Landau levels in SSs. Thermopower hence provides a powerful tool to investigate correlated Dirac fermions in topological insulators. Our observations demonstrate that Dirac topological SSs exhibit strongly correlated phases in a high magnetic field, and would enable studies of a variety of exotic fractional quantum Hall physics and other correlated phenomena in this newly discovered chiral Dirac system.

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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