Prof. Dr. Jianshu Cao
Department of Chemistry, MIT Cambridge
spricht zum Thema:
Quantum Coherence in Light-harvesting Energy Transfer
Quantum coherence plays a central role in light-harvesting systems and organic semiconductors and will be reported in the case studies of FMO (Fenna-Mathews-Olson protein complex of green sulfur bacteria), LH2 (Light Harvesting complex 2 of purple bacteria), and the Holstein model.
- We have developed a systematic procedure to map quantum networks to kinetic networks and used the rate kernel to define the spatial-temporal coherence. [1] For light-harvesting networks, we can further establish an identity among steady-state coherence, flux, and efficiency of energy transfer [2]. The application to FMO reveals the dominant role of Forster-like hopping in the down-hill energy funnel. [1]
- The B850 ring of LH2 (bacteriochlorophyll protein complex with the absorption peak at 850 cm-1) displays exciton delocalization and system-bath correlation (i.e., the polaron effect). We have developed new methods [3] [4] to account for the system-bath correlation and predicted dark-state emission and dark-state energy transfer in LH2 B850 rings.
- To explore the role of vibronic coherence, we have calculated phonon-assisted exciton dynamics in the tilted Holstein model and predicted the fractional vibronic resonance, which has implications for the antenna effect and quantum transport [5]
[1] Efficient energy transfer in light-harvesting systems: Quantum-classical comparison, flux network, and robustness analysis. Wu, Liu, Ma, Silbey, and Cao, JCP 137, 174111 (2012)
[2] Steady-State Analysis of Light-harvesting Energy Transfer Driven by Incoherent Light: From Dimers to Networks. Yang and Cao, J. Phys. Chem. Lett. 11, 7204-7211 (2020).
[3] Forster resonance energy transfer, absorption and emission spectra in multi-chromophoric systems. I-III. Moix, Ma, Cao, JCP 142 (9), p094108 (2015)
[4] Construction of multichromophoric spectra from monomer data: Applications to resonant energy transfer. Chenu and Cao, Phys. Rev. Lett. 118, 013001 (2017)
[5] Long-range nonequilibrium coherent tunneling induced by fractional vibronic resonances. Kessing, Yang, Manmana, and Cao, J. Phys. Chem. Lett. 13, 6831–6838 (2022).
Interessenten sind herzlich eingeladen.
Prof. Dr. Kühn