Simulating Photodissociation in Strong Field Enabled by the Random Phase Thermal Wavefunction Approach.

Simulating photodissociation becomes challenging when the number of states involved grows large. The computational complexity is usually reduced by restrictions that limit the model's scope. We present a first-principles quantum model for strong-field photodissociation that treats rotational dynamics explicitly. The random-phase thermal wavefunction method reduces the large computational cost. The simulation yields experimental observables, such as the momentum angular distribution of the photofragments. We study how these observables converge at two field intensities, with each set at a different temperature. The method is designed to reach conditions where exact numerical methods become intractable; here, we validate it against exact results in the regime where both are available. Beyond the conventional dependence on system size and number of realizations, we find that convergence depends on the observable's sensitivity to coherence.