We establish a generalized picture of the phase sensitivity of laser-induced directional bond breaking using the ${\mathrm{H}}_2$ molecule as the example. We show that the well-known proton ejection anisotropy measured with few-cycle pulses as a function of their carrier-envelope phases 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 larger molecules.

• Received 5 April 2020
• Accepted 18 June 2020

DOI:https://doi.org/10.1103/PhysRevLett.125.023202