Orbital dynamics in 2D topological and Chern insulators

TL;DR

This paper analytically investigates how second-order magnetic field corrections affect the electronic and transport properties of 2D topological and Chern insulators, revealing tunable diamagnetic susceptibility at low fields.

Contribution

It provides analytical expressions for magnetic field-induced changes in Berry curvature, orbital magnetic moment, and density of states in 2D topological insulators.

Findings

Identification of zero-field diamagnetic susceptibility.

Analytical formulas for Berry curvature and orbital magnetic moment modifications.

Relevance of corrections at low magnetic fields due to small energy gaps.

Abstract

Within a relativistic quantum formalism we examine the role of second-order corrections caused by the application of magnetic fields in two-dimensional topological and Chern insulators. This allows to reach analytical expressions for the change of the Berry curvature, orbital magnetic moment, density of states and energy determining their canonical grand potential and transport properties. The present corrections, which become relevant at relatively low fields due to the small gap characterizing these systems, unveil a zero-field diamagnetic susceptibility which can be tuned by the external magnetic field.