A challenging task in surface science is to unravel the dynamics of molecules on surfaces associated with, for example, surface molecular motion and (bimolecular) reactions. As these processes typically take place on femtosecond time scales, ultrafast lasers must be used in these studies. We demonstrate two complementary approaches to study these ultrafast molecular dynamics at metal surfaces. In the first, the molecules are studied after desorbing from the surface initiated by a laser pulse using the so called time-of-flight technique. In the second approach, molecules are studied in real time during their diffusion over the surface by using surface-specific pump-probe spectroscopy.
KeywordsFemtosecond Laser Pump Pulse Stretch Vibration Coupling Time Step Site
This work is part of the research program of the “Stichting voor Fundamenteel Onderzoek der Materie (FOM),” which is financially supported by the “Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO).” We are grateful to A.W. Kleyn, A. Eichler, M. Persson, M. Forsblom, H. Ueba, and M. Wolf for their help, many useful discussions, and comments.
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