Dynamical effects in electron tunnelling: Nonlocal image potentials

Abstract

We generalize Jonson's nonlocal theory of dynamical exchange-correlation potential in tunnelling to the metal-insulator-metal (M-I-M) case, for zero and nonzero tunnelling currents, and solve in the second order exactly including surface effects. The correct treatment removes unphysical features near interfaces. The nonlocal calculation gives dynamical image potentials reduced in comparison to the classical image potential, but this reduction is less drastic than in the local approximation.