Tunneling dynamics of electrons and effective tunneling potential

Abstract

The problem of tunneling of electrons in scanning tunneling microscopy is considered in the framework of a many-particle approach, which is based on the concept of effective tunneling potential (ETP). This method makes it possible to identify three spatial regions of tunneling of an electron: (i) the main region of electron localization (MREL) of the surface; (ii) the MREL of the tip; and (iii) the asymptotic region (AR). We discuss the mechanisms of direct and combined tunneling transitions. The features of tunneling dynamics are studied with the use of partial amplitudes of centre-to-centre (tip-surface) tunneling transitions. The total state-to-state amplitude and tunneling current are expressed as a superposition of the partial tunneling amplitudes.