Electron Force Microscopy: Single electron tunneling to electron states at insulator surfaces

Description
Single electron tunneling between a Scanning Probe tip and an oxide surface has been demonstrated in the laboratory of C.C. Williams. In this method, an Electrostatic Force Microscope is used to detect abrupt single electron tunneling events when a bias voltage is applied between the tip and surface, and the tip comes within tunneling range (<2 nm). Single electrons can be manipulated between tip and surface by changing the polarity of the tip/sample voltage. Images of the surface before and after the tunneling events show the electron at the surface.

Implications
Such tunneling provides a means of characterizing single electronic states, both in location and energy, in completely insulating materials. After further development, it should provide a method to characterize the electronic properties of single molecules.

Research Group Contacts
Clayton Williams, Physics, http://www.physics.utah.edu/people/faculty/cwilliams.html

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