The evaluation of non-topological components in Berry phase and momentum relaxation time in a gapped 3D topological insulator

TL;DR

This paper investigates how non-topological factors like higher order terms and magnetic fields influence the Berry phase, momentum relaxation time, and magneto-conductivity in gapped 3D topological insulators, providing more accurate theoretical predictions.

Contribution

It introduces the effects of higher order $ oldsymbol{k}$ terms and magnetic fields on Berry phase and transport properties in gapped 3D topological insulators.

Findings

Alteration of Berry phase from $(2n + 1)\pi$ due to higher order terms and magnetic field.

Modification of momentum relaxation time in the presence of warping and magnetic effects.

Changes in magneto-conductivity tensors linked to non-topological influences.

Abstract

The zero gap surface states of a 3D-topological insulator host Dirac fermions with spin locked to the momentum. The gap-less Dirac fermions exhibit electronic behaviour different from those predicted in conventional materials. While calculations based on a simple linear dispersion can account for observed experimental patterns, a more accurate match is obtained by including higher order $ \overrightarrow{k}$ terms in the Hamiltonian. In this work, in presence of a time reversal symmetry breaking external magnetic field and higher order warping term, alteration to the topologically ordained Berry phase of $ (2n + 1)\pi $, momentum relaxation time, and the magneto-conductivity tensors is established.