ACOUSTIC-MODE COUPLING AND ELECTRON HEATING IN THIN METAL-FILMS

We discuss the heating of electrons by a steady-state electric field in an unbounded thin metal film by considering the energy flow from the electron system to the acoustic modes of the film. Using the dispersion relationships and the resulting density of states for the acoustic modes calculated from a non-Debye model, and a deformation potential coupling between the electrons and the acoustic modes, it is shown that the relationship between the electric field and the electron temperature is dependent on the coupling between acoustic modes at the surface of the film. At low excitation we show the energy relaxation is dominated by the antisymmetric Rayleigh mode.