Coherent energy transfer

Edington M D, Riter R E and Beck W F 1995 Evidence for coherent energy transfer in allophycocyanin trimers J. Phys. Chem. 99 15 699-704... 

If the conditions for Forster transfer are not applicable, then the theory must be extended. There is recently experimental evidence that coherent energy transfer participates in photosynthesis [74, 75], In this case, the participating molecules are very close together. The excited state of the donor does not completely relax to the Boltzmann distribution before the energy can be shared with the acceptor, and the transfer can no longer be described by a Forster mechanism. We will not discuss this case. There has been active discussion of coherent transfer and very strong interactions in the literature for a longer time [69], and references can be found in some more recent papers [70-72, 76, 77],... 

Simulated coherent energy transfer in a hydrogen bonded amide chain arising from Fermi resonance has been modelled by Clarke and Collins . This interesting study is related to the Davydov soliton model which has been proposed for explaining energy transport in proteins. The role of similar nonlinear effects in simple organised chemical systems has yet to be established. 

Recent concerns about overly chaotic motion in classical system [7] and the zero point energy problem [8] have led us to begin to explore the limitations of classical MD simulation. In the context ofnano-fluidic systems, this would translate into whether or not it would be possible to study shock and pressure waves at the nanometer size scale using MD simulation. Of course, MD simulation has enabled reasonably accurate calculations of fluid viscosities [9] however, the phenomenon of fluid Viscosity, at the atomic level, does not require coherent energy transfer. 

The nanotube was kept static in each simulation reported here so that the motion of the nanotube would not perturb fee fluid flow. In other words, conditions were made as favorable as possible for coherent energy transfer. Also, fee system was equilibrated for 2 ps before fee introduction of any shock waves or external forces. The flow region was about 100 A, long ... 

Recently scientists found that these pigments flex in sync. .. R. Hildner et al. Quantum coherent energy transfer over varying pathways in single light-harvesting complexes. 2013. Science 340(6139), p. 1448. DOI 10.1126/science. 1235820. 

Pullerits T, Chachisvilis M, Fedchenia I and Sundstrom V 1994 Coherent versus incoherent energy transfer in the lightharvesting complexes of photosynthetic bacteria Lietuvos Fizikos Zurnalas 34 329-38... 

NES is an elastic and coherent scattering process, i.e., it takes place without energy transfer to electronic or vibronic states and is delocalized over many nuclei. Owing to the temporal and spatial coherence of the radiation field in the sample. 

In ESR, it is also customary to classify relaxation processes by their effects on electron and nuclear spins. A process that involves an electron spin flip necessarily involves energy transfer to or from the lattice and is therefore a contribution to Tx we call such a process nonsecular. A process that involves no spin flips, but which results in loss of phase coherence, is termed secular. Processes that involve nuclear spin flips but not electron spin flips are, from the point of view of the electron spins, nonsecular, but because the energy transferred is so small (compared with electron spin flips) these processes are termed pseudosecular. 

Leegwater, J. A. (1996). Coherent versus incoherent energy transfer and trapping in photosynthetic antenna complexes. J. Phys. Chem. 100, 14403-9. 

Klimov, V., Sekatskii, S. K. and Dietler, G. (2004). Coherent fluorescence resonance energy transfer between two dipoles Full quantum electrodynamics approach. J. Mod. Opt. 51, 1919 -7. 

Ray, J. and Makri, N. (1999). Short range coherence in the energy transfer of photosynthetic light harvest-ing systems. J. Phys. Chem. 103, 9417. 

The events taking place in the RCs within the timescale of ps and sub-ps ranges usually involve vibrational relaxation, internal conversion, and photo-induced electron and energy transfers. It is important to note that in order to observe such ultrafast processes, ultrashort pulse laser spectroscopic techniques are often employed. In such cases, from the uncertainty principle AEAt Ti/2, one can see that a number of states can be coherently (or simultaneously) excited. In this case, the observed time-resolved spectra contain the information of the dynamics of both populations and coherences (or phases) of the system. Due to the dynamical contribution of coherences, the quantum beat is often observed in the fs time-resolved experiments. 

Ishizaki A, Fleming GR (2009) Unified treatment of quantum coherent and incoherent hopping dynamics in electronic energy transfer reduced hierarchy equation approach. J Chem Phys 130 234111... 

Describing complex wave-packet motion on the two coupled potential energy surfaces, this quantity is also of interest since it can be monitored in femtosecond pump-probe experiments [163]. In fact, it has been shown in Ref. 126 employing again the quasi-classical approximation (104) that the time-and frequency-resolved stimulated emission spectrum is nicely reproduced by the PO calculation. Hence vibronic POs may provide a clear and physically appealing interpretation of femtosecond experiments reflecting coherent electron transfer. We note that POs have also been used in semiclassical trace formulas to calculate spectral response functions [3]. 

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