Selectively exciting desorption

Surface Chemistry Reactions of molecules adsorbed on surfaces can be induced by injecting electrons from the tip of a scanning tunneling microscope. Rusimova et al. show that for the tip-induced desorption of toluene molecules from a silicon surface, two activation channels exist: One is invariant, but the other depends on the height of the tip above the surface. When the tip is very close to the molecule, it can quench the excitation. The decreased lifetime, in turn, decreases the desorption probability. Science , this issue p. [1012][1] [1]: /lookup/doi/10.1126/science.aat9688