Non-Hermitian approach for modeling of noise-assisted quantum electron transfer in photosynthetic complexes

Abstract

We model the quantum electron transfer (ET) in the photosynthetic reaction center (RC), using a non-Hermitian Hamiltonian approach. Our model includes (i) two protein cofactors, donor and acceptor, with discrete energy levels and (ii) a third protein pigment (sink) which has a continuous energy spectrum. Interactions are introduced between the donor and acceptor, and between the acceptor and the sink, with noise acting between the donor and acceptor. The noise is considered classically (as an external random force), and it is described by an ensemble of two-level systems (random fluctuators). Each fluctuator has two independent parameters, an amplitude and a switching rate. We represent the noise by a set of fluctuators with fitting parameters (boundaries of switching rates), which allows us to build a desired spectral density of noise in a wide range of frequencies. We analyze the quantum dynamics and the efficiency of the ET as a function of (i) the energy gap between the donor and acceptor, (ii) the strength of the interaction with the continuum, and (iii) noise parameters. As an example, numerical results are presented for the ET through the active pathway in a quinone-type photosystem II RC.

15 pages, 8 figures

References in corpus (5)

• Environment-Assisted Quantum Transport
• Decoherence of flux qubits due to 1/f flux noise
• Decoherence in qubits due to low-frequency noise
• Non-Gaussian dephasing in flux qubits due to 1/f-noise
• Non-hermitian exciton dynamics in a photosynthetic unit system

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• Efficient quantum transport in a multi-site system combining classical noise and quantum baths
• Noise-assisted quantum electron transfer in photosynthetic complexes
• Possible Role of Interference and Sink Effects in Nonphotochemical Quenching in Photosynthetic Complexes
• On Improving the Performance of Nonphotochemical Quenching in CP29 Light-Harvesting Antenna Complex
• Multi-Scale Exciton and Electron Transfer in Multi-Level Donor-Acceptor System
• Decoherence and Spin Echo in Biological Systems
• Non-Hermitian Hamiltonian Approach for Two-Dimensional Coherent Spectra of Driven Systems