Nonlinear Properties of Gated Graphene in a Strong Electromagnetic Field

TL;DR

This paper develops a microscopic theory describing how strong electromagnetic fields interact with gated bilayer graphene, revealing phenomena like electron population inversion and excitonic absorption.

Contribution

It introduces a quantum kinetic framework for analyzing nonlinear optical properties of gated graphene under intense laser fields.

Findings

Population inversion at resonant photon energy

Excitonic absorption in gapped graphene monolayers

Theoretical insights into nonlinear optical responses

Abstract

We develop a microscopic theory of a strong electromagnetic field interaction with gated bilayer graphene. Quantum kinetic equations for density matrix are obtained using a tight binding approach within second quantized Hamiltonian in an intense laser field. We show that adiabatically changing the gate potentials with time may produce (at resonant photon energy) a full inversion of the electron population with high density between valence and conduction bands. In the linear regime, excitonic absorption of an electromagnetic radiation in a graphene monolayer with opened energy gap is also studied.