Theory of resonant photon drag in monolayer graphene

Abstract

Photon drag current in monolayer graphene with degenerate electron gas is studied under interband excitation near the threshold of fundamental transitions. Two main mechanisms generate an emergence of electron current. Nonresonant drag effect results from direct transfer of in-plane photon momentum $\mathbf{q}$ to electron and dependence of matrix elements of transitions on $\mathbf{q}$. Resonant drag effect (RDE) originates from $\mathbf{q}$-dependent selection of transitions due to a sharp form of the Fermi distribution in energy. The drag current essentially depends on the polarization of radiation and, in general, is not parallel to $\mathbf{q}$. The perpendicular current component appears if the in-plain electric field is tilted toward $\mathbf{q}$. The RDE has no smallness connected with $q$ and exists in a narrow region of photon frequency $\ensuremath{\omega}$, $|\ensuremath{\hbar}\ensuremath{\omega}\ensuremath{-}2{ϵ}_{F}|<\ensuremath{\hbar}sq$, where $s$ is the electron velocity.