Hierarchical approach based on stochastic decoupling to dissipative systems

158

258

The dynamics of excitation energy transfer within the B850 ring of light harvesting complex 2 from Rhodobacter sphaeroides and between neighboring B850 rings is investigated by means of dissipative quantum mechanics. The assumption of Boltzmann populated donor states for the calculation of intercomplex excitation transfer rates by generalized Förster theory is shown to give accurate results since intracomplex exciton relaxation to near-Boltzmann population exciton states occurs within a few picoseconds. The primary channels of exciton transfer between B850 rings are found to be the five lowest-lying exciton states, with non-850 nm exciton states making significant contributions to the total transfer rate.

Section: ͑13͒mentioning

confidence: 99%

Light harvesting complex II B850 excitation dynamics

Strümpfer¹,

Schulten²

2009

158

258

“…A modified Redfield theory 32,33 has been developed to go beyond weak system-bath coupling and applied to model the effect of vibronic coupling on the electronic relaxation rates in light-harvesting proteins. 17 The hierarchy equations of motion (HEOM) [34][35][36][37][38][39][40][41][42][43] method provides a computationally expensive, yet accurate way to model open quantum systems beyond the Markovian and perturbative approximations by introducing a set of auxiliary density operators. In recent years, the multi-configuration time-dependent Hartree (MCTDH) method, [44][45][46] where the multidimensional vibrational wavefunctions are described as a linear combination of the Hartree products of single-mode wave functions, has been used to describe e.g., the role of vibronic coupling in ultrafast charge transfer dynamics at an OPV donor-acceptor heterojunction.…”

Section: Introductionmentioning

confidence: 99%

Quantum dynamics of a vibronically coupled linear chain using a surrogate Hamiltonian approach

Lee

Troisi

2016

Vibronic coupling between the electronic and vibrational degrees of freedom has been reported to play an important role in charge and exciton transport in organic photovoltaic materials, molecular aggregates and light-harvesting complexes. Explicitly accounting for effective vibrational modes rather than treating them as a thermal environment has been shown to be crucial to describe the effect of vibronic coupling. We present a methodology to study dissipative quantum dynamics of vibronically coupled systems based on a surrogate Hamiltonian approach, which is in principle not limited by Markov approximation or weak system-bath interaction, using a vibronic basis. We apply vibronic surrogate Hamiltonian method to a linear chain system and discuss how different types of relaxation process, intramolecular vibrational relaxation and intermolecular vibronic relaxation, influence population dynamics of dissipative vibronic systems.

“…Both unbiased and biased two-site systems are considered with ε 12 = 0 and 100 cm −1 . To be compared with the calculation of the hierarchy equation, [35][36][37][38] a quantum bath with the Debye spectral density is applied, given by…”

Section: Quantum Kinetic Expansion In a Two-site Systemmentioning

confidence: 99%

“…In this paper, all the exact quantities are obtained using the hierarchy equation method. [35][36][37][38] In Sec. IV, the RQKE rate kernels are used to predict the detailed population evolution and are calibrated with the exact result.…”

Section: Introductionmentioning

confidence: 99%

A continued fraction resummation form of bath relaxation effect in the spin-boson model

Gong

Tang

Mukamel

et al. 2015

Articles you may be interested inIn the spin-boson model, a continued fraction form is proposed to systematically resum high-order quantum kinetic expansion (QKE) rate kernels, accounting for the bath relaxation effect beyond the second-order perturbation. In particular, the analytical expression of the sixth-order QKE rate kernel is derived for resummation. With higher-order correction terms systematically extracted from higher-order rate kernels, the resummed quantum kinetic expansion approach in the continued fraction form extends the Pade approximation and can fully recover the exact quantum dynamics as the expansion order increases. C 2015 AIP Publishing LLC. [http://dx