Mixed quantum-classical modelling of nonequilibrium vibrational energy transport

• Applicant: Dr. Johan Runeson
• Subject Area: Theoretical Condensed Matter Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 431945604

The project aims to find the appropriate level of theory - ranging from fully quantum to fully classical mechanics - to accurately describe vibrational energy transport in biomolecules. It is well-known that standard classical calculations can lead to incorrect rates of intramolecular energy transfer due to their lack of quantum effects, such as the zero-point energy of high-frequency modes. However, little is known about how correctly account for these quantum effects, especially in the out-of-equilibrium regime relevant for recent photo-switch protein experiments. We aim to explain how quantum corrections manifest themselves in vibrational energy transfer as well as to quantify their magnitude in the experimentally relevant settings. To achieve this goal, we will construct a reduced system-bath model describing the transfer network of complex proteins, target it with fully quantum, fully classical, as well as mixed quantum-classical dynamics, and explore how moving the boundary between the quantum and classical subsystems influences the energy transfer.

• DFG Programme: Research Units
• Subproject of: FOR 5099: Reducing complexity of nonequilibrium systems
• Co-Investigator: Professor Dr. Gerhard Stock