Theoretical study of current and barrier height between aluminum tip and silicon surface in scanning tunneling microscopy

The first-principles calculations for the electronic structure of the aluminum tip and the silicon surface in scanning tunneling microscopy are performed using the recursion-transfer matrix method, which is an effective method for exploring the microscopic electronic states of a bielectrode system under electric field and current. The atomic-scale current distribution and the potential barrier between the tip and the surface are presented. It is revealed that the opening of a hole in the potential barrier occurs when the tip-sample distance is 10 a.u. at a surface bias of +2.0 V.