Anomalous Hall Response in Two Dimensional Topological Insulators due to the Stark Effect

TL;DR

This paper demonstrates how external electric fields induce matrix dipole moments in 2D topological insulators, modifying their Hall responses and leading to measurable changes in transverse currents for both quantum anomalous and spin Hall effects.

Contribution

It introduces a novel effect where electric field-induced dipole moments alter Hall responses, adding new terms to the conductance in 2D topological insulators.

Findings

Transverse currents in quantum anomalous Hall effect gain an extra term proportional to the time derivative of electric field.

Simultaneous spin and charge transverse currents appear in quantum spin Hall effect due to dipole moments.

The coupling between edge channels and electromagnetic fields is modified, enabling new experimental measurements.

Abstract

It is shown that the presence of matrix dipole moments induced by external electric fields can modify the Hall response in two dimensional Topological insulators. In the case of the Quantum Anomalous Hall effect the induced transverse currents acquire an extra term being proportional to the Hall conductance and the time derivative of the applied electric field. In the case of the Quantum Spin Hall effect both a spin and charge transverse currents appear simultaneously. In virtue of the bulk-edge correspondence the coupling between the chiral edge channels and the electromagnetic field changes allowing for an extra non minimal coupling term. Both effects can be measured through transport and tunnelling experiments.