Metal-insulator transition in graphene induced by circularly polarized photons

TL;DR

This paper theoretically demonstrates that circularly polarized light can induce a metal-insulator transition in graphene by creating bound electron-photon states with an energy gap, suggesting a way to control graphene's electronic properties with light.

Contribution

It provides exact solutions to the electron-photon Dirac equation showing how circularly polarized photons induce a dielectric energy gap in graphene, leading to a metal-insulator transition.

Findings

Photon-induced energy gap in graphene's spectrum.

Formation of bound electron-photon quasiparticles.

Potential observation with laser-generated circularly polarized light.

Abstract

Exact stationary solutions of the electron-photon Dirac equation are obtained to describe the strong interaction between massless Dirac fermions in graphene and circularly polarized photons. It follows from them that this interaction forms bound electron-photon states which should be considered as a kind of charged quasiparticles. The energy spectrum of the quasiparticles is of dielectric type and characterized by an energy gap between the valence and conductivity bands. Therefore the electron-photon interaction results in metal-insulator transition in graphene. The stationary energy gap, induced by photons, and concomitant effects can be observed for graphene exposed to a laser-generated circularly polarized electromagnetic wave.