Large photon drag effect of intrinsic graphene induced by plasmonic evanescent field

TL;DR

This paper predicts a significant photon drag effect in intrinsic graphene induced by plasmonic evanescent fields, where surface plasmons transfer large momentum to carriers, generating a directional current.

Contribution

It introduces a model for photon drag in graphene enhanced by plasmonic layers, highlighting the role of surface plasmon wave vectors and evanescent fields in carrier dynamics.

Findings

Surface plasmons increase photon wave number by hundreds of times.

Directional macroscopic current depends on laser incident angle and intensity.

Model predicts large photon drag effect in graphene-on-plasmonic-layer systems.

Abstract

Large photon drag effect of the massless Dirac Fermions in intrinsic graphene is predicted for a graphene-on-plasmonic-layer system. The surface plasmons in the plasmonic layer enlarge the wave number of photon for hundreds of time of that in vacuum. The evanescent field of the surface plasmons generates directional motion of carriers in the intrinsic graphene, because of the large momentum transfer from the surface plasmon to the excited carriers. A model Hamiltonian is developed on the assumption that the in-plane wavelength of the surface plasmons is much smaller than the mean free path of the carriers. The time evolution of density matrix is solved by perturbation method as well as numerical integration. The non-diagonal density matrix elements with momentum transfer lead to gauge current that is the optically driven macroscopic direct current. The dependence of the macroscopic direct current on the incident direction and intensity of the laser field is studied.