Surface plasmon drag effect in a dielectrically modulated metallic thin film.

We have experimentally and numerically investigated photo-induced voltage (PIV) effect across a Au film with a dielectric grating. We observed strongly enhanced voltage when surface plasmon polariton (SPP) is excited. It was found that electrons in the Au film are driven to the propagation direction of SPP. We have numerically shown that dissipative force called as scattering force well elucidates the experimental result for the first time. It is also clarified that this effect can be attributed to the momentum transfer from SPP to free carriers in the Au film. Thus the effect we observed can be called as surface plasmon drag effect in analogy with the photon drag effect.