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arXiv · 1611.00612

Effects of system-bath coupling on Photosynthetic heat engine: A polaron master equation approach

Abstract

In this paper, we apply the polaron master equation, which offers the possibilities to interpolate between weak and strong system-bath coupling, to study how system-bath couplings affect charge transfer processes in Photosystem II reaction center (PSII RC) inspired quantum heat engine (QHE) model in a wide parameter range. The effects of bath correlation and temperature, together with the combined effects of these factors are also discussed in details. The results show a variety of dynamical behaviours. We interpret these results in terms of noise-assisted transport effect and dynamical localization which correspond to two mechanisms underpinning the transfer process in photosynthetic complexes: One is resonance energy transfer and the other is dynamical localization effect captured by the polaron master equation. The effects of system-bath coupling and bath correlation are incorporated in the effective system-bath coupling strength determining whether noise-assisted transport effect or dynamical localization dominates the dynamics and temperature modulates the balance of the two mechanisms. Furthermore, these two mechanisms can be attributed to one physical origin: bath-induced fluctuations. The two mechanisms is manifestations of dual role played by bath-induced fluctuations within respective parameter range. In addition, we find that the effec- tive voltage of QHE exhibits superior robustness with respect to the bath noise as long as the system-coupling strength is not too large.

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M Qin, H Z Shen, X L Zhao, X X Yi. 2016-11-03. Effects of system-bath coupling on Photosynthetic heat engine: A polaron master equation approach. https://doi.org/10.1103/physreva.96.012125

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