We demonstrate that dissociative ionization of O2 can be controlled by the relative delay between an attosecond pulse train (APT) and a copropagating infrared (IR) field. Our experiments reveal a dependence of both the branching ratios between a range of electronic states and the fragment angular distributions on the extreme ultraviolet (XUV) to IR time delay. The observations go beyond adiabatic propagation of dissociative wave packets on IR-induced quasistatic potential energy curves and are understood in terms of an IR-induced coupling between electronic states in the molecular ion.

Phys. Rev. A

Siu, W., Kelkensberg, F., Gademann, G., Rouzée, A., Johnsson, P., Dowek, D., … Vrakking, M. J. J. (2011). Attosecond control of dissociative ionization of O2 molecules. Phys. Rev. A, 84(6, Article number: 63412), 1–4. doi:10.1103/PhysRevA.84.063412