NonMarkovian Quantum State Diffusion for temperaturedependent linear spectra of light harvesting aggregates
Abstract
NonMarkovian Quantum State Diffusion (NMQSD) has turned out to be an efficient method to calculate excitonic properties of aggregates composed of organic chromophores, taking into account the coupling of electronic transitions to vibrational modes of the chromophores. NMQSD is an open quantum system approach that incorporates environmental degrees of freedom (the vibrations in our case) in a stochastic way. We show in this paper that for linear optical spectra (absorption, circular dichroism), no stochastics is needed, even for finite temperatures. Thus, the spectra can be obtained by propagating a single trajectory. To this end, we map a finite temperature environment to the zero temperature case using the socalled thermofield method. The resulting equations can then be solved efficiently by standard integrators.
 Authors:
 MaxPlanckInstitut für Physik komplexer Systeme, Nöthnitzer Str. 38, D01187 Dresden (Germany)
 Institut für Theoretische Physik, Technische Universität Dresden, D01062 Dresden (Germany)
 Publication Date:
 OSTI Identifier:
 22416005
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION SPECTRA; COUPLING; DEGREES OF FREEDOM; DICHROISM; DIFFUSION; EXCITONS; MARKOV PROCESS; QUANTUM STATES; QUANTUM SYSTEMS; STANDARDS; TEMPERATURE DEPENDENCE; TRAJECTORIES; VISIBLE RADIATION
Citation Formats
Ritschel, Gerhard, Möbius, Sebastian, Eisfeld, Alexander, Email: eisfeld@mpipksdresden.mpg.de, Suess, Daniel, and Strunz, Walter T. NonMarkovian Quantum State Diffusion for temperaturedependent linear spectra of light harvesting aggregates. United States: N. p., 2015.
Web. doi:10.1063/1.4905327.
Ritschel, Gerhard, Möbius, Sebastian, Eisfeld, Alexander, Email: eisfeld@mpipksdresden.mpg.de, Suess, Daniel, & Strunz, Walter T. NonMarkovian Quantum State Diffusion for temperaturedependent linear spectra of light harvesting aggregates. United States. doi:10.1063/1.4905327.
Ritschel, Gerhard, Möbius, Sebastian, Eisfeld, Alexander, Email: eisfeld@mpipksdresden.mpg.de, Suess, Daniel, and Strunz, Walter T. 2015.
"NonMarkovian Quantum State Diffusion for temperaturedependent linear spectra of light harvesting aggregates". United States.
doi:10.1063/1.4905327.
@article{osti_22416005,
title = {NonMarkovian Quantum State Diffusion for temperaturedependent linear spectra of light harvesting aggregates},
author = {Ritschel, Gerhard and Möbius, Sebastian and Eisfeld, Alexander, Email: eisfeld@mpipksdresden.mpg.de and Suess, Daniel and Strunz, Walter T.},
abstractNote = {NonMarkovian Quantum State Diffusion (NMQSD) has turned out to be an efficient method to calculate excitonic properties of aggregates composed of organic chromophores, taking into account the coupling of electronic transitions to vibrational modes of the chromophores. NMQSD is an open quantum system approach that incorporates environmental degrees of freedom (the vibrations in our case) in a stochastic way. We show in this paper that for linear optical spectra (absorption, circular dichroism), no stochastics is needed, even for finite temperatures. Thus, the spectra can be obtained by propagating a single trajectory. To this end, we map a finite temperature environment to the zero temperature case using the socalled thermofield method. The resulting equations can then be solved efficiently by standard integrators.},
doi = {10.1063/1.4905327},
journal = {Journal of Chemical Physics},
number = 3,
volume = 142,
place = {United States},
year = 2015,
month = 1
}

NonMarkovian dynamics is studied for two interacting qubits strongly coupled to a dissipative bosonic environment. We derive a nonMarkovian quantumstatediffusion (QSD) equation for the coupled twoqubit system without any approximations, and in particular, without the Markov approximation. As an application and illustration of our derived timelocal QSD equation, we investigate the temporal behavior of quantum coherence dynamics. In particular, we find a strongly nonMarkovian regime where entanglement generation is significantly modulated by the environmental memory. Additionally, we study residual entanglement in the steady state by analyzing the steadystate solution of the QSD equation. Finally, we discuss an approximate QSD equation.

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