Generalized phase-sensitivity of directional bond-breaking in laser-molecule interaction

We establish a generalized picture of the phase-sensitivity of laser-induced directional bond-breaking using the H${}_2$ molecule as the example. We show that the well-known proton ejection anisotropy measured with few-cycle pulses arises as an amplitude-modulation of an intrinsic anisotropy that is sensitive to the laser phase at the ionization time and determined by the molecule’s electronic structure. Our work furthermore reveals a strong electron-proton correlation that may open up a new approach to experimentally accessing the laser-sub-cycle intramolecular electron dynamics also in large molecules.