Two-mode Floquet fewest switches surface hopping for nonadiabatic dynamics driven by two-frequency laser fields

Area of Science:

• Quantum dynamics
• Laser-matter interactions
• Computational chemistry

Background:

• Two-frequency laser fields offer precise control over molecular motion.
• Existing theoretical methods for simulating laser-driven nonadiabatic dynamics are limited in accuracy and scalability.
• Developing robust computational tools is crucial for harnessing laser fields in chemical reactions.

Purpose of the Study:

• To develop and validate a novel computational approach for simulating molecular dynamics under two-frequency laser fields.
• To provide a reliable and scalable theoretical framework for studying nonadiabatic processes driven by bichromatic laser fields.
• To enable the design and simulation of two-frequency laser control protocols.

Main Methods:

• Development of the two-mode Floquet fewest switches surface hopping (two-mode F-FSSH) algorithm.
• Implementation within a mixed quantum-classical framework.
• Validation using three driven one-dimensional two-state models (Rabi and avoided-crossing scattering models).

Main Results:

• The two-mode F-FSSH approach demonstrates good agreement with numerically exact split-operator calculations.
• Accurate simulation of electronic and nuclear dynamics across various initial conditions and field parameters.
• Successful benchmarking against established models, confirming the method's reliability.

Conclusions:

• The developed two-mode F-FSSH method is a practical and accurate tool for simulating laser-driven molecular dynamics.
• This framework facilitates the design and exploration of two-frequency laser control strategies.
• The approach shows promise for extension to more complex and realistic molecular systems.