Sub-7-femtosecond conical-intersection dynamics probed at the carbon K-edge

Abstract

How fast is electronic relaxation? Technical advances in extending spectroscopy to the attosecond time scale has caused considerable interest in experimental studies of various ultrafast processes that were previously inaccessible. Using attosecond transient absorption around the carbon K-edge accompanied by ab initio quantum dynamics simulations, Zinchenko et al. investigated ultrafast, non-adiabatic dynamics in the ethylene cation. They directly observed the electronic D 1 → D 0 relaxation mediated by the conical intersection taking place within 7 femtoseconds, far shorter than any vibrational period or any previously reported electronic relaxation. The demonstrated technique is directly applicable to liquids and solutions, enabling further studies of charge- and energy-transfer dynamics of organic molecules in chemical and biochemical systems. Science , this issue p. 489