A multi-site variational master equation approach to dissipative energy transfer

Felix A Pollock, Dara P. S. McCutcheon, Brendon W Lovett, Erik M Gauger, Ahsan Nazir

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Abstract

Unitary transformations can allow one to study open quantum systems in situations for which standard, weak-coupling type approximations are not valid. We develop here an extension of the variational (polaron) transformation approach to open system dynamics, which applies to arbitrarily large exciton transport networks with local environments. After deriving a time-local master equation in the transformed frame, we go on to compare the population dynamics predicted using our technique with other established master equations. The variational frame dynamics are found to agree with both weak coupling and full polaron master equations in their respective regions of validity. In parameter regimes considered difficult for these methods, the dynamics predicted by our technique are found to interpolate between the two. The variational method thus gives insight, across a broad range of parameters, into the competition between coherent and incoherent processes in determining the dynamical behaviour of energy transfer networks.

Original languageEnglish
Article number075018
Number of pages16
JournalNew Journal of Physics
Volume15
DOIs
Publication statusPublished - Jul 2013

Keywords

  • REDUCED DENSITY-MATRICES
  • QUANTUM TIME EVOLUTION
  • PHYSIOLOGICAL TEMPERATURE
  • EXCITATION TRANSFER
  • TENSOR PROPAGATOR
  • POLARON MOTION
  • COHERENCE
  • DYNAMICS
  • SYSTEMS
  • SPECTRA

Cite this

Pollock, F. A., McCutcheon, D. P. S., Lovett, B. W., Gauger, E. M., & Nazir, A. (2013). A multi-site variational master equation approach to dissipative energy transfer. New Journal of Physics, 15, [075018]. https://doi.org/10.1088/1367-2630/15/7/075018