Assess the accuracy of decoherence corrections in F-FSSH near multiple LICIs

Determine the overall effect of conventional decoherence corrections, including the energy-based decoherence correction, on the accuracy of Floquet fewest-switches surface hopping dynamics near single or multiple light-induced conical intersections, particularly when repeated wave-packet passages generate nuclear coherence and recoherence.

Background

The paper benchmarks two-mode Floquet fewest-switches surface hopping (F-FSSH) against numerically exact quantum wave-packet dynamics for Na2 driven by a bichromatic laser field and supporting two light-induced conical intersections (LICIs). The exact dynamics exhibit persistent population and alignment oscillations attributed to repeated wave-packet splitting, recombination, interference, and recurrence near the LICIs.

The authors identify two distinct coherence problems in standard F-FSSH: electronic overcoherence along individual trajectories and the inability of independent trajectories to retain relative nuclear phases and reconstruct interference or recoherence. They note that conventional corrections such as the energy-based decoherence correction may reduce intratrajectory electronic overcoherence but cannot restore relative nuclear phases between trajectories. The unresolved issue is therefore whether, and to what extent, such corrections improve F-FSSH accuracy in the repeated-passage regime.