Estimation of friction of a single chemisorbed molecule on a surface using incident atoms

Friction of a single molecule chemisorbed on a surface is a very fundamental property related to the dynamics of the diffusion of the molecule. We used a newly developed method, in which energy-controlled rare gas atoms collide with CO molecules on a stepped surface to displace CO molecules from initial terrace sites to final step sites. The friction coefficient of CO molecules on the surface was determined directly by comparing the experimentally measured increase in the number of CO molecules at step sites with classical molecular dynamics simulation results.