High Field (up to 140kOe) Angle Dependent Magneto Transport of Bi2Te3 Single Crystals

TL;DR

This study investigates the angle-dependent magneto-transport properties of Bi2Te3 single crystals under high magnetic fields up to 140kOe, revealing linear magnetoresistance, weak anti-localization effects, and a single Dirac cone in the bulk material.

Contribution

It provides detailed high-field magneto-transport data on Bi2Te3 single crystals, including angular dependence, weak anti-localization signatures, and ARPES confirmation of a single Dirac cone.

Findings

Magneto-resistance follows cos Theta dependence with field orientation.

Linear magnetoresistance observed up to 140kOe.

Presence of a single Dirac cone confirmed by ARPES.

Abstract

We report the angle dependent high field (up to 140kOe) magneto transport of Bi2Te3 single crystals, a well-known topological insulator. The crystals were grown from melt of constituent elements via solid state reaction route by self-flux method. Details of crystal growth along with their brief characterization up to 5 Tesla applied field was reported by some of us recently [J. Magn. Mag. Mater. 428, 213 (2017)]. The angle dependence of the magneto-resistance (MR) of Bi2Te3 follows the cos Theta function i.e., MR is responsive, when the applied field is perpendicular (tilt angle Theta = o and/or 180) to the transport current. The low field (10 kOe) MR showed the signatures of weak anti localization (WAL) character with typical cusp near origin at 5 K. Further, the MR is linear right up to highest applied field of 140 kOe. The large positive MR are observed up to high temperatures and are above 250 and 150 percent at 140 kOe in perpendicular fields at 50 K and 100 K respectively. Heat capacity CP(T) measurements revealed the value of Debye temperature to be 135 K. ARPES (angle resolved photoemission spectroscopy) data clearly showed that the bulk Bi2Te3 single crystal consists of a single Dirac cone.