Figure 5

(a) Combined image of the energy contour map superimposed on the integral intensity map, which was produced by the C-mode operation result. (b) Energy contour map produced by the C-mode operation result superimposed on the integral intensity map of the two-probe measurement. Markers on the map show the characteristic point. (▲: mountain-like potential, ■: valley-like potential, *: saddle-like potential, which is an unstable point). The shaded area has higher energy (> 2.657 eV) than the local excitation point (point P: ●) by S-probe.