What is the theory behind Scanning Tunneling Microscopy (STM) technique?

[ovidiut]

hi to everyone!
who can help me with a almost and understandable complete theory of Scanning tunneling Microscopy technique?
with my best wishes
O.

 

[Gokul43201]

There are entire books written on the theory of STM.

From: http://www.chemistry.adelaide.edu.au/external/soc-rel/content/stm.htm

Scanning-tunneling microscopy (STM) can image surfaces of conducting materials with atomic-scale resolution. It uses an atomically-sharp metal tip that is brought very close to the surface. When the tip and sample are connected with a voltage source, a small tunneling current flows between the tip and sample surface. This current can be measured, and the magnitude depends on the distance between the tip and the surface. As the tip is moved laterally across the surface, a feedback mechanism moves the tip up and down to maintain a constant tunneling current. Rastering the tip across the surface therefore produces a topographic map of the surface.

More detailed explanation :
http://www.llnl.gov/str/Scan.html

Tutorials and problems :
http://www.chembio.uoguelph.ca/educmat/chm729/STMpage/stmtutor.htm

IBM Almaden Labs uses the STM as a materials synthesis tool (to perform atomic re-arrangements) - their image gallery is really neat :
http://www.almaden.ibm.com/vis/stm/stm.html