Efficient construction of generalized master equation memory kernels for multi-state systems from nonadiabatic...

Area of Science:

• Quantum dynamics
• Computational chemistry
• Photosynthesis research

Background:

• Generalized quantum master equation (GQME) methods are crucial for understanding energy and charge transfer in complex systems.
• Recent advances combine GQME with quantum-classical methods for improved accuracy and efficiency over traditional approaches.

Purpose of the Study:

• To develop and accelerate quantum-classical methods based on the GQME framework.
• To accurately simulate energy transfer dynamics in photosynthetic complexes.

Main Methods:

• Nonperturbative combination of GQME with quantum-classical methods.
• Development of an algorithm for selective sampling of memory kernel elements.
• Application of Ehrenfest mean field theory with GQME (MF-GQME) to FMO and LHCII models.

Main Results:

• Quantum-classical GQME trajectory scaling is at most quadratic with subsystem states.
• The MF-GQME accurately captures ultrafast (femtosecond) and longer (picosecond) dynamical time scales in LHCII.
• Complex dynamics spanning picoseconds are encoded in a memory kernel decaying around 65 fs.

Conclusions:

• Accelerated quantum-classical GQME methods provide a powerful tool for simulating complex quantum dynamics.
• The MF-GQME approach accurately models energy transfer in photosynthetic light-harvesting complexes.
• This work advances the computational study of quantum phenomena in biological and material systems.