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arXiv · 1512.01442

2D layered transport properties from topological insulator Bi$_2$Se$_3$ single crystals and micro flakes

Olivio Chiatti·Christian Riha·Dominic Lawrenz·Marco Busch·Srujana Dusari·Jaime Sánchez-Barriga·Anna Mogilatenko·Lada V. Yashina·Sergio Valencia·Akin A. Ünal·Oliver Rader·Saskia F. Fischer
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Abstract

Low-field magnetotransport measurements of topological insulators such as Bi$_2$Se$_3$ are important for revealing the nature of topological surface states by quantum corrections to the conductivity, such as weak-antilocalization. Recently, a rich variety of high-field magnetotransport properties in the regime of high electron densities ($\sim10^{19}$ cm$^{-3}$) were reported, which can be related to additional two-dimensional layered conductivity, hampering the identification of the topological surface states. Here, we report that quantum corrections to the electronic conduction are dominated by the surface states for a semiconducting case, which can be analyzed by the Hikami-Larkin-Nagaoka model for two coupled surfaces in the case of strong spin-orbit interaction. However, in the metallic-like case this analysis fails and additional two-dimensional contributions need to be accounted for. Shubnikov-de Haas oscillations and quantized Hall resistance prove as strong indications for the two-dimensional layered metallic behavior. Temperature-dependent magnetotransport properties of high-quality Bi$_2$Se$_3$ single crystalline exfoliated macro and micro flakes are combined with high resolution transmission electron microscopy and energy-dispersive x-ray spectroscopy, confirming the structure and stoichiometry. Angle-resolved photoemission spectroscopy proves a single-Dirac-cone surface state and a well-defined bulk band gap in topological insulating state. Spatially resolved core-level photoelectron microscopy demonstrates the surface stability.

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Olivio Chiatti, Christian Riha, Dominic Lawrenz, Marco Busch, Srujana Dusari, Jaime Sánchez-Barriga, Anna Mogilatenko, Lada V. Yashina, Sergio Valencia, Akin A. Ünal, Oliver Rader, Saskia F. Fischer. 2015-12-04. 2D layered transport properties from topological insulator Bi$_2$Se$_3$ single crystals and micro flakes. https://doi.org/10.1038/srep27483

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