Local tunneling barrier height measurement on Au(111)

The systematic local tunneling barrier height (LBH) measurement on a Au(111) surface has been carried out in order to clarify the origin of the previously-reported peculiar behaviors; extremely small LBH values and its strong gap-distance dependence. In our study where carefully chosen tunneling tips are used, the LBH of Au(111) shows no such anomalies, indicating that these peculiar behaviors are artifacts due to tip-sample interaction. Furthermore, the bias and distance dependence of the LBH of Au(111) obtained here can be explained well by the simplified one-dimensional rectangular potential model for tunneling, which is similar to the case of Pt(111).