Progress in ultrafast scanning probe microscopy

Ultrafast Scanning Probe Microscopy (USPM) has exciting potential to create movies of surface dynamics. By improving the sensitivity, dynamic range, and time resolution of this technique, one will be able to animate surface dynamics by collecting a series of Scanning Tunneling Microscope (STM) images for increasing values of time delay. This will allow dynamical phenomena to be studied in real space with atomic resolution. Such a tool will open a window for the observation of processes and excitations which propagate at velocities of a few angstrom per fs (or less). It should be possible to spatially resolve in real time phenomena such as vibronic motion on the atomic scale, carrier transport in semiconductor structures, electric field and voltage wavefront propagation at metal semiconductor interfaces. The operation of sub-micron electronic/optoelectronic devices can be directly characterized with such a technique.