Resonant vibrational-electronic coupling between photosynthetic excitons is inadequately described by reduced basis sets

• Main Authors: Sahu, Amitav, Tiwari, Vivek
• Other Authors: Asian Spectroscopy Conference 2020
• Format: Conference or Workshop Item
• Language: English
• Published: 2020
• Subjects: Science::Chemistry; Vibrational-electronic Coupling; Photosynthesis
• Online Access: https://hdl.handle.net/10356/144228
• Institution: Nanyang Technological University

Ultrafast internal conversion between excited states of photosynthetic pigments has been a subject of intense spectroscopic interest owing to its near unity quantum yield. Of particular interest is the possibility of strong non-adiabatic mixing between vibrational and electronic degrees of freedom, termed as vibronic mixing, caused by resonances between exciton energy gaps and dense low-frequency vibrational spectrum of photosynthetic pigments. Several reports have implicated coherent superpositions of vibronically mixed excitons to explain experimental signatures, and vibronic exciton quantum dynamical simulations have further suggested a possible functional role for quantum superpositions in enhancing the rates of energy and charge delocalization. A key question which arises in this context is -- what are the unique properties of excitons coupled through resonant vibronic coupling, and whether these properties could be well approximated in basis sets with reduced vibrational dimensionality without over-simplifying the expected excited state dynamics? The above question will be the main theme of this presentation.