Tight-binding analysis of surface electronic conduction measured with micro-multipoint scanning tunneling microscopy probes

To analyze electronic conduction through surface states in micro-multipoint measurements using scanning tunneling microscopy, we calculated electron density and current distribution in a surface with Tamm states of a simple cubic lattice using a tight-binding method with the Hückel approximation. Both wave function and Green's function methods were employed in the calculations, and two peaks of the transmission spectrum were obtained at -1.10 and 2.91 eV using both methods. The analysis of current distribution revealed that the transmission at 2.91 eV mainly corresponds to surface state conduction, whereas that at 2.91 eV includes bulk state conduction. These results suggest that whether or not a measured conductance corresponds to pure surface state conduction is dependent on the energy of injected electrons.