Scanning Tunneling MicrosopyBasics

Transmission coefficientcritically dependent on the

distance btw. tip & surf.

Electron energy level densities

Electron flow

A bias voltage needs to be applied:

DVbias is necessary to raise the Fermi level and create free levelsfor the electrons. Tunneling probability depends on the existence (and density) of free levels.

DVbias is positive or negative with reference to the tip’s Fermi level.

Basics of tunneling

Atomic Force Microsopy-