Laser-Assisted Scanning Tunneling Microscopy

The scanning tunneling microscope (STM) was the starting point for the development of numerous new methods to obtain atom-resolved surface information. In the usual mode the STM produces images of the local density of states at the surface. New modifications of the STM allow the generation of surface images with quantities such as atomic forces, photon emission, temperature, and ion conductance, as well as images with spectroscopic information. In some of these experiments new modes of operation have been introduced where the distance dependence of these quantities is used to control the width of the tunneling gap of the STM.