  Light-matter momentum transfer in plasmonic materials is theoretically
discussed in the framework of plasmonic pressure mechanism taking into account
non-equilibrium electron dynamics and thermalization process. We show that our
approach explains the experimentally observed relationship between the
plasmon-related electromotive force and absorption and allows one to correctly
predict the magnitude of the plasmon drag emf in flat metal films. We extend
our theory to metal films with modulated profiles and show that the simple
relationship between plasmonic energy and momentum transfer holds at relatively
small amplitudes of height modulation and an approximation of laminar electron
drift. Theoretical groundwork is laid for further investigations of
shape-controlled plasmon drag in nanostructured metal.
