| Abstract [eng] |
The function of many biological molecular systems is closely tied to the process of energy relaxation. Understanding the pathways and rates of energy relaxation induced by photoexcitation is relevant across a range of molecular spatial scales. This includes the smallest molecules, intermediate-sized molecular aggregates, and the largest photosynthetic complexes found in nature, which may involve physical processes such as molecular energy relaxation, charge transfer, and spatial energy transfer across structures composed of tens or hundreds of molecules. The work explores the use of the family of Davydov’s trial wavefunctions, which expand the model’s vibrational eigenstates in terms of time-dependent coherent states. During time evolution, these wavefunctions continuously adjust to align with the most relevant eigenstates at any given moment. As excitation energy relaxation occurs in the model, the temperature of the model increases. The standard approaches lack a direct energy exchange mechanism between vibrational degrees of freedom, violating the assumption of constant temperature and introduces errors. The theoretical problem of vibrational heating mirrors a natural process, during which a large amount of thermal energy to its immediate surroundings. Subsequently, a cooling process – thermalization, occurs where the excess heat dissipates away from the molecules. This work proposes a theoretical formulation, implementation and investigation of thermalization to be used with Davydov’s trial wavefunctions. |
