Multi-quanta energy relaxation in a nonlinear quantum dimer coupled to a phonon bath

Pouthier, Vincent

doi:10.1016/j.physd.2006.06.014

Cited by 14 publications

(5 citation statements)

References 48 publications

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“…20 This approach has gained a renewed attention due to the recent interest in energy transfer in light harvesting systems [21][22][23] and has been extended to study non-equilibrium quantum transport. 24 In this work, we will use a variant of the polaron based master equation which has the same structure as the popular Redfield equation.…”

Section: Theorymentioning

confidence: 99%

Coherent quantum transport in disordered systems: A unified polaron treatment of hopping and band-like transport

Lee

Moix

Cao

2015

The Journal of Chemical Physics

103

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Quantum transport in disordered systems is studied using a polaron-based master equation. The polaron approach is capable of bridging the results from the coherent band-like transport regime governed by the Redfield equation to incoherent hopping transport in the classical regime. A non-monotonic dependence of the diffusion coefficient is observed both as a function of temperature and system-phonon coupling strength. In the band-like transport regime, the diffusion coefficient is shown to be linearly proportional to the system-phonon coupling strength and vanishes at zero coupling due to Anderson localization. In the opposite classical hopping regime, we correctly recover the dynamics described by the Fermi's Golden Rule and establish that the scaling of the diffusion coefficient depends on the phonon bath relaxation time. In both the hopping and band-like transport regimes, it is demonstrated that at low temperature, the zero-point fluctuations of the bath lead to non-zero transport rates and hence a finite diffusion constant. Application to rubrene and other organic semiconductor materials shows a good agreement with experimental mobility data. C 2015 AIP Publishing LLC. [http://dx

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Section: Theorymentioning

confidence: 99%

Coherent quantum transport in disordered systems: A unified polaron treatment of hopping and band-like transport

Lee

Moix

Cao

2015

The Journal of Chemical Physics

103

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“…In a recent series of papers, a small polaron approach has been used to describe how narrow band excitons may promote vibrational energy flow in a lattice of H-bonded peptide units [1][2][3][4][5]. These works were based on the seminal model introduced by Davydov and Kisluka [6], and later by Scott [7], to describe bioenergy transport in α-helices in terms of a soliton mechanism.…”

Section: Introductionmentioning

confidence: 99%

Narrow band exciton coupled with acoustical anharmonic phonons: application to the vibrational energy flow in a lattice of H-bonded peptide units

Pouthier

2009

J. Phys.: Condens. Matter

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A time-convolutionless master equation is established for describing the transport properties of amide-I vibrons coupled with acoustic phonons in a lattice of H-bonded peptide units. Within the non-adiabatic weak coupling limit, it is shown that the vibron dynamics strongly depends on the nature of the phonons and two distinct mechanisms have been identified. Harmonic phonons, which support spatial correlations over an infinite length scale, induce a fast dephasing-rephasing mechanism in the short time limit. Consequently, the vibron keeps its wavelike nature and a coherent vibrational energy flow takes place whatever the temperature. By contrast, anharmonic phonons carry spatial correlations over a finite length scale, only. As a result, the rephasing process no longer compensates the dephasing mechanism so that dephasing-limited band motion occurs. It gives rise to the incoherent diffusion of the vibron characterized by a diffusion coefficient whose temperature dependence scales as 1/T(α). In the weak anharmonicity limit, the exponent α is about 2. It becomes smaller than unity in the strong anharmonicity limit, indicating that the diffusion coefficient behaves as a slowly decaying function of the temperature.

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“…In such cases it is possible to overcome the limitations imposed by Eq. ( 8) by performing a polaron-transformation [82][83][84][85], which models the dynamics of an exciton followed by nuclear deformations, 2), ( 14), and ( 15) for the OPV and PPV-like materials considered in Secs. III A and III B, expressed in Hartree atomic units [31].…”

Section: Master Equationmentioning

confidence: 99%

Exciton transport in amorphous polymers and the role of morphology and thermalisation

Campaioli,

Cole

2021

Preprint

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Understanding the transport mechanism of electronic excitations in conjugated polymers is key to advancing organic optoelectronic applications, such as solar cells, OLEDs and flexible electronics. While crystalline polymers can be studied using solid-state techniques based on lattice periodicity, the characterisation of amorphous polymers is hindered by an intermediate regime of disorder and the associated lack of symmetries. To overcome these hurdles we use a reduced state quantum master equation approach based on the Merrifield exciton formalism. Using this model we study exciton transport in conjugated polymers and its dependence on morphology and temperature. Exciton dynamics consists of a thermalisation process, whose features depend on the relative strength of thermal energy, electronic couplings and disorder, resulting in remarkably different transport regimes. By applying this method to representative systems based on poly(p-phenylene vinylene) (PPV) we obtain insight into the role of temperature and disorder on localisation, charge separation, non-equilibrium dynamics, and experimental accessibility of thermal equilibrium states of excitons in amorphous polymers.

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Multi-quanta energy relaxation in a nonlinear quantum dimer coupled to a phonon bath

Cited by 14 publications

References 48 publications

Coherent quantum transport in disordered systems: A unified polaron treatment of hopping and band-like transport

Coherent quantum transport in disordered systems: A unified polaron treatment of hopping and band-like transport

Narrow band exciton coupled with acoustical anharmonic phonons: application to the vibrational energy flow in a lattice of H-bonded peptide units

Exciton transport in amorphous polymers and the role of morphology and thermalisation

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