Investigation of Angle dependent SdH oscillations in Topological Insulator Bismuth

TL;DR

This study investigates the angle-dependent Shubnikov-de Haas oscillations in Bismuth, revealing its topological nature through magneto-transport measurements, band structure calculations, and the dependence of oscillations on magnetic field orientation.

Contribution

It provides a detailed analysis of angle-dependent magneto-transport in Bismuth, confirming its topological properties via Z2 invariants and band structure calculations.

Findings

Positive out-of-plane magnetoresistance up to 104% at 2 K and 10 T

Oscillations fade with increasing angle between field and current

Hybrid functional calculations show non-trivial topological bands

Abstract

The current article investigated the band structure in the presence and absence of spin-orbit coupling (SOC), examined the Z2 invariants, and investigated the detailed angle-dependent magneto-transport of up to 10 T (Tesla) and down to 2 K for the Bismuth crystal. The out-of-plane field-dependent magnetoresistance (MR) is positive and is huge to the order of ~104% at 2 K and 10 T. On the other hand, the longitudinal (in-plane) field-dependent MR is relatively small and is negative. The thermal activation energy is also estimated by using the Boltzmann formula from resistivity vs temperature measurement under applied transverse magnetic fields. The topological nature of Bi is confirmed by Z2 invariant calculation using Density functional theory. PBESol bands show trivial but Hybrid functional (HSE) bands show non-trivial topology being present in Bismuth. This article comprehensively studies the dependence of MR oscillations upon the angle between the applied field and the current. The observed oscillations fade away as the angle is increased. This article is an extension of our previous work on Bismuth [1], in which we conducted a comprehensive analysis of its structural and micro-structural properties along with its transport behavior in an applied transverse magnetic field.