A microscopic theory of STM-induced CO desorption from Cu(111)

We propose a microscopic theory to describe the dynamics of STM-induced des orption of CO from Cu(111). In the theory, a single electron initially occu pies the CO 2 pi* orbital, and the CO-Cu stretching vibration, described by a Morse potential, is in the ground state. An excitation of the CO-Cu stre tching vibration occurs when this electron subsequently transfers/tunnels f rom the CO 2 pi* orbital to the metal. The excitation of the CO-Cu stretchi ng vibration to an unbound state leads to CO desorption from Cu(111). Our c alculation results for the desorption probability agree with experimental r esults, and show the same isotope effects as those observed experimentally. (C) 1999 Elsevier Science B.V. All rights reserved.