Abstract

A prominent feature of topological insulators (TIs) is the surface states comprising of spin-nondegenerate massless Dirac fermions. Recent technical advances have made it possible to address the surface transport properties of TI thin films by tuning the Fermi levels of both top and bottom surfaces. Here we report our discovery of a novel planar Hall effect (PHE) from the TI surface, which results from a hitherto-unknown resistivity anisotropy induced by an in-plane magnetic field. This effect is observed in dual-gated devices of bulk-insulating Bi2−xSbxTe3 thin films, where the field-induced anisotropy presents a strong dependence on the gate voltage with a characteristic two-peak structure near the Dirac point. The origin of PHE is the peculiar time-reversal-breaking effect of an in-plane magnetic field, which anisotropically lifts the protection of surface Dirac fermions from backscattering. The observed PHE provides a useful tool to analyze and manipulate the topological protection of the TI surface.

Details

Title
Planar Hall effect from the surface of topological insulators
Author
Taskin, A A 1 ; Legg, Henry F 2 ; Yang, Fan 1 ; Sasaki, Satoshi 3   VIAFID ORCID Logo  ; Kanai, Yasushi 4 ; Matsumoto, Kazuhiko 4 ; Rosch, Achim 2 ; Ando, Yoichi 1   VIAFID ORCID Logo 

1  Physics Institute II, University of Cologne, Köln, Germany 
2  Institute for Theoretical Physics, University of Cologne, Köln, Germany 
3  Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan; School of Physics and Astronomy, University of Leeds, Leeds, UK 
4  Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan 
Pages
1-7
Publication year
2017
Publication date
Nov 2017
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41467-017-01474-8
ProQuest document ID
1961025590
Copyright
© 2017. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.