Using a simple theoretical model we have simulated the conditions under which a scanning tunneling microscope is able to transport a physisorbed xenon atom sitting on a nickel (110) surface. Simple calculations of the tunnel current for the atomic geometries derived using the former model are in good agreement with an elegant experiment performed by Eigler and Schweizer on the same system [Nature 344, 524 (1990)]. On these theoretical grounds, we discuss in detail how different conditions affect the transport process for this system.

• Received 8 October 1991

DOI:https://doi.org/10.1103/PhysRevB.45.8721