Ohmic damping of center-of-mass oscillations of a molecular monolayer

The electrostatic moments on the atoms or molecules of a monolayer solid are the source of an electric field with spatial variation determined by the reciprocal-lattice vectors of the monolayer. Center-of-mass oscillations of the monolayer generate an oscillating electric field in a metallic substrate. The contribution of the resulting Ohmic loss to the damping of the oscillation on a normal metal is evaluated for adsorption dipole moments, with parameters for Xe/Ag(111), and for the molecular quadrupole moments in a monolayer herringbone lattice, with parameters for N-2/Pb and N-2/Ag(111). The analysis is very similar to the theory of the anomalous skin effect: the anomalous response arises because the spatial length scale of the driving field is small compared to the mean free path of electrons in the normal metal.