Magnetic field-dependent resistance crossover and anomalous magnetoresistance in topological insulator Bi2Te3

Anand Nivedan; Kamal Das; Sandeep Kumar; Arvind Singh; Sougata Mardanya; Amit Agarwal; Sunil Kumar

doi:10.1088/1361-648X/aba06e

Magnetic field-dependent resistance crossover and anomalous magnetoresistance in topological insulator Bi₂Te₃

J Phys Condens Matter. 2020 Jul 23;32(42). doi: 10.1088/1361-648X/aba06e.

Authors

Anand Nivedan¹, Kamal Das², Sandeep Kumar¹, Arvind Singh¹, Sougata Mardanya², Amit Agarwal², Sunil Kumar¹

Affiliations

¹ Department of Physics, Indian Institute of Technology Delhi, New Delhi-110016, India.
² Department of Physics, Indian Institute of Technology Kanpur, Kanpur-208016, India.

PMID: 32590365
DOI: 10.1088/1361-648X/aba06e

Abstract

We report a metal-insulator like transition in single-crystalline 3D topological insulator Bi₂Te₃at a temperature of 230 K in the presence of an external magnetic field applied normal to the surface. This transition becomes more prominent at larger magnetic field strength with the residual resistance value increasing linearly with the magnetic field. At low temperature, the magnetic field dependence of the magnetoresistance shows a transition from logarithmic to linear behavior and the onset magnetic field value for this transition decreases with increasing temperature. The logarithmic magnetoresistance indicates the weak anti-localization of the surface Dirac electrons while the high temperature behavior originates from the bulk carriers due to intrinsic impurities. At even higher temperatures beyond ∼230 K, a completely classical Lorentz model type quadratic behavior of the magnetoresistance is observed. We also show that the experimentally observed anomalies at ∼230 K in the magneto-transport properties do not originate from any stacking fault in Bi₂Te₃.

Keywords: density functional theory; magnetoresistance; topological insulator; weak anti-localization.