Generalized Phase Sensitivity of Directional Bond Breaking in the Laser-Molecule Interaction

Area of Science:

• Physical Chemistry
• Quantum Mechanics
• Molecular Dynamics

Background:

• Laser-induced bond breaking is a fundamental process in chemistry.
• Understanding molecular response to ultrashort laser pulses is crucial for controlling chemical reactions.
• Proton ejection anisotropy in H2 dissociation has been previously observed.

Purpose of the Study:

• To generalize the understanding of phase sensitivity in laser-induced directional bond breaking.
• To elucidate the role of carrier-envelope phase in molecular dissociation dynamics.
• To explore electron-proton correlations during laser-matter interactions.

Main Methods:

• Theoretical modeling of laser-induced dissociation of H2.
• Analysis of proton ejection anisotropy as a function of laser pulse carrier-envelope phase.
• Investigation of the electronic structure's influence on dissociation pathways.

Main Results:

• The proton ejection anisotropy is an amplitude modulation of an intrinsic molecular anisotropy.
• This intrinsic anisotropy is sensitive to the laser phase at the moment of ionization.
• A strong correlation between electron and proton dynamics was identified.

Conclusions:

• The carrier-envelope phase of few-cycle laser pulses modulates the intrinsic anisotropy of H2 dissociation.
• This phase sensitivity provides a new route to probe sub-cycle electron dynamics in molecules.
• The findings may be extendable to larger molecules for studying ultrafast electron behavior.