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06:42
Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
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Why Quantum Coherence Is Not Important in the Fenna-Matthews-Olsen Complex
David M Wilkins1,2,3, Nikesh S Dattani1,2,3
1Physical and Theoretical Chemistry Laboratory, Oxford University , South Parks Road, Oxford, OX1 3QZ, United Kingdom.
Journal of Chemical Theory and Computation
|November 18, 2015
Summary
We improved the Hierarchical Equations of Motion (HEOM) method, reducing memory costs by 75%. This enables exact calculations of photosynthetic energy transfer, revealing coherence may not enhance, and can even hinder, efficiency.
Area of Science:
- Quantum biology
- Computational chemistry
- Photosynthesis research
Background:
- The Hierarchical Equations of Motion (HEOM) is a standard method for simulating quantum dynamics.
- Accurate simulations of energy transfer in light-harvesting complexes are crucial for understanding photosynthesis.
Purpose of the Study:
- To develop an improved HEOM technique with reduced computational cost.
- To obtain exact, converged results for the FMO trimer's population dynamics.
- To investigate the role of quantum coherence in photosynthetic energy transfer.
Main Methods:
- Developed a memory-efficient variant of the HEOM method.
- Performed full population dynamics calculations for the 24-site FMO trimer.
- Compared exact results with approximations and incoherent Förster theory.
Main Results:
- The improved HEOM method reduces memory cost by up to 75% with maintained accuracy.
- Achieved the first fully converged, exact results for the 7-site FMO monomer subsystem and the 24-site trimer.
- Exact results deviate from previous approximations.
- Energy transfer time scales are similar with or without coherence.
Conclusions:
- Quantum coherence does not appear to significantly improve energy transfer efficiency in the studied system.
- Incoherent Förster theory can overpredict energy transfer rates.
- Quantum coherence might, in some cases, decelerate the photosynthetic process.
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