Portal de Periódicos da CAPES

Independent particle descriptions of tunneling using the many-body quantum transport approach

2006; American Physical Society; Volume: 73; Issue: 24 Linguagem: Inglês

10.1103/physrevb.73.241314

1550-235X

Giorgos Fagas, Paul Delaney, James C. Greer,

Surface and Thin Film Phenomena

Currents across thin insulators are commonly taken as single electrons moving across classically forbidden regions; this independent particle picture is well-known to describe most tunneling phenomena. Examining quantum transport from a different perspective, i.e., by explicit treatment of electron-electron interactions, we evaluate different single particle approximations with specific application to tunneling in metal-molecule-metal junctions. We find maximizing the overlap of a Slater determinant composed of single particle states to the many-body current-carrying state is more important than energy minimization for defining single particle approximations in a system with open boundary conditions. Thus the most suitable single particle effective potential is not one commonly in use by electronic structure methods, such as the Hartree-Fock or Kohn-Sham approximations.