Wave packet bifurcation in ultrafast hydrogen migration in CH3OH+ by pump-probe coincidence momentum imaging with few-cycle laser pulses

摘要

Ultrafast nuclear dynamics in CH3OH+ has been studied based on the released kinetic energy distributions of the fragment ions in the non-migration (CH3OH2+ --> CH3+ + OH+) and migration (CH3OH2+ --> CH2+ + OH2+) pathways obtained by pump-probe coincidence momentum imaging with few-cycle laser pulses (6.0(5) fs, 2.1(2) x 10(14) W/cm(2)). A characteristic oscillatory structure with a bifurcation at similar to 150 fs in the kinetic energy distribution of the migration pathway is interpreted as the motion of a vibrational wave packet on a bound well around the migrated geometry, oscillating first along the C-O bond and bifurcating into bound and dissociating components. (C) 2015 Elsevier B.V. All rights reserved.