抄録
Scanning tunneling microscopy (STM) has made it possible not only to observe atomic structures and electronic states of surfaces with atomic resolutions but also to modify surface structures in atomic scale. To investigate atomic processes and electronic processes induced by the STM tip, a first-principles recursion-transfer matrix (RTM) method has been developed. In this article the RTM method is introduced, and examples of application of the method to atom manipulation and atomic contact are presented. Adiabatic potential surfaces of atom extracted from a silicon surface to an aluminum tip under applied bias voltage are calculated, and decrease of activation barrier is discussed in terms of the changes of electron density distributions around the atom. Current density and tunneling barrier distributions are also clarified in detail, and the formation of atomic contact with approach of a tip is described.
