Quantum Optomagnetics in Graphene

TL;DR

This paper models the inverse Faraday effect in graphene, showing how intense circularly polarized light induces a measurable DC magnetization and optical activity through a quantum mechanical approach.

Contribution

It provides a novel quantum mechanical model of optomagnetism in graphene, deriving analytical expressions for magnetization and optical rotation under circularly polarized light.

Findings

Analytical expression for DC magnetization in graphene.

Prediction of measurable polarization rotation angles.

Quantum model based on dressed states of quasi-electrons.

Abstract

Graphene can be magnetized through nonlinear response of its orbital angular momentum to an intense circularly polarized light. This optomagnetic effect can be well exemplified by the Inverse Faraday Effect (IFE) where an optically-generated DC magnetization leads to graphene's optical activity. We provide a single-particle quantum mechanical model of an IFE in graphene by solving Schr\"odinger's equation in the presence of a renormalized Hamiltonian near a Dirac point in the presence of circularly polarized monochromatic light. We derive an analytical expression for DC magnetization based on non-perturbative and dressed states of quasi-electrons where their energy spectrum is isotropically gapped by the circularly polarized light. Optical rotatory power is then computed through the gyroelectric birefringence where a measurable polarization rotation angle under moderate and intense optical radiations is predicted.