A new pump & dump strategy to control chemical reactivity at surfaces: application to photoisomerization of adsorbates

A new `pump & dumpʹ strategy to control reactivity in or at the condensed phase is proposed. In an optical pump step, an educt (ensemble) is excited to an intermediate state with an ultrashort laser pulse. The stabilization of a desired product configuration, which is achieved in the `ordinaryʹ pump & dump approach by a second, dump pulse, is taken over by energy relaxation. The new method is applied to the ground electronic state isomerization of a molecule (NH3) adsorbed on a metal surface (Cu(111)).