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Floquet-Engineered Photodissociation Simulated Using Coupled Potential Energy and Dipole Matrices
Chris Avanessian1, Yuchen Wang1, David R Yarkony1
1Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States.
External laser fields dramatically alter ammonia photodissociation pathways by creating light-induced conical intersections. This light-dipole interaction significantly changes the branching ratio of ground and excited state NH2, highlighting nonadiabatic effects.
Area of Science:
- Chemical Physics
- Molecular Dynamics
- Photochemistry
Background:
- Ammonia photodissociation is a key process in atmospheric chemistry.
- Nonadiabatic effects play a crucial role in molecular dynamics following light absorption.
Purpose of the Study:
- To investigate the influence of external laser fields on ammonia photodissociation dynamics.
- To explore the formation and impact of light-induced conical intersections (LICIs).
Main Methods:
- Simulated nonadiabatic molecular dynamics using an approximate Floquet Hamiltonian.
- Employed quasiclassical trajectories with diabatic potential energy matrices (DPEM) and dipole matrices.
- Analyzed the effects of laser-dipole interaction on potential energy surfaces.
Main Results:
- External laser fields induce seams of light-induced conical intersection (LICI).
- LICIs significantly alter the topography of coupled potential energy surfaces.
- The branching ratio of ground and excited state NH2 is drastically changed by laser-dipole interaction.
Conclusions:
- Laser-dipole interaction is a significant factor in ammonia photodissociation.
- Nonadiabatic effects induced by light play a critical role in determining product distributions.
- This study provides insights into light-driven molecular dynamics and control.
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