Photo-induced Hall Effect in Graphene -- Effect of Boundary Types

TL;DR

This paper predicts a topologically-originated Hall effect in graphene induced by circularly polarized light, without magnetic fields, using advanced theoretical methods, and examines the influence of boundary conditions.

Contribution

It introduces a theoretical prediction of a photo-induced Hall effect in graphene with boundary condition analysis, utilizing the Keldysh Green's function and Floquet methods.

Findings

AC field induces a non-quantized Hall effect in graphene.

Dynamical gap and Hall effect have a topological origin.

Boundary conditions affect the Hall response.

Abstract

We theoretically predict, with the Keldysh Green's function combined with the Floquet method, that the AC electric field of a circularly polarized light should induce a Hall effect, in the absence of uniform magnetic fields, in graphene with a pair of Dirac dispersions. Although the Hall coefficient is not quantized, the dynamical gap generated by the AC field and the associated Hall effect bear a topological origin which can be traced back to the Dirac cones. We also study the dependence on boundary conditions. The required AC field strength is estimated to be realistic.