Theoretical studies of molecular scale near-field electron dynamics

摘要

Near-field scanning microscopy and nonlinear spectroscopy on a molecular scale involve weakly interacting subsystems that dynamically exchange electrons and electromagnetic energy.The theoretical description of such processes requires unified approach to the electron-near-field dynamics.By considering electronic structure and dynamics of two distant clusters or atoms we show that adiabatic local spin-density approximation (ALSDA)fails to describe (even qualitatively)essential details of electron dynamics in weakly interacting systems.A recently developed functional addresses these ailments within a time-dependent setting.With this method we study the spectroscopy of a composite system,namely,two weakly coupled metallic clusters.The near-field (dipole-dipole)coupling and electron transfer display an interesting interplay,producing exponential sensitivity of emission yield to the intercomponent distance.