Sampling Scanning Tunneling Microscope
Original Publication Date: 1988-Apr-01
Included in the Prior Art Database: 2005-Feb-15
The temporal resolution of most existing scanning tunneling microscopes is limted to a few kilohertz although the tunnel effect per se is extremely fast. The discrepancy essentially results from the stray capacitance Cts between tip and sample, and from the tunnel resistance Rts . With a typical value of Cts = 1-10 pF, and Rts = 10 ML, a temporal resolution tlimit = 10-100 ms results. Lowering of tlimit will permit better use of the resolution powers of the scanning tunneling microscope and allow the observation of dynamic phenomena on the near-atomic level. A sampling technique based on mechanical modulation of the tunnel gap width as herein proposed will push the temporal resolution of the scanning tunneling microscope down to about 1 ns.