Accurate nonadiabatic quantum dynamics on the cheap: Making the most of mean field theory with master equations
Abstract
In this article, we show how Ehrenfest mean field theory can be made both a more accurate and efficient method to treat nonadiabatic quantum dynamics by combining it with the generalized quantum master equation framework. The resulting mean field generalized quantum master equation (MFGQME) approach is a nonperturbative and nonMarkovian theory to treat open quantum systems without any restrictions on the form of the Hamiltonian that it can be applied to. By studying relaxation dynamics in a wide range of dynamical regimes, typical of charge and energy transfer, we show that MFGQME provides a much higher accuracy than a direct application of mean field theory. In addition, these increases in accuracy are accompanied by computational speedups of between one and two orders of magnitude that become larger as the system becomes more nonadiabatic. This combination of quantumclassical theory and master equation techniques thus makes it possible to obtain the accuracy of much more computationally expensive approaches at a cost lower than even mean field dynamics, providing the ability to treat the quantum dynamics of atomistic condensed phase systems for long times.
 Authors:
 Department of Chemistry, Stanford University, Stanford, California 94305 (United States)
 Department of Physics, Stanford University, Stanford, California 94305 (United States)
 Publication Date:
 OSTI Identifier:
 22416206
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 9; 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; ACCURACY; ENERGY TRANSFER; EQUATIONS; HAMILTONIANS; MARKOV PROCESS; MEANFIELD THEORY; QUANTUM SYSTEMS; RELAXATION; VELOCITY
Citation Formats
Kelly, Aaron, Markland, Thomas E., Email: tmarkland@stanford.edu, and Brackbill, Nora. Accurate nonadiabatic quantum dynamics on the cheap: Making the most of mean field theory with master equations. United States: N. p., 2015.
Web. doi:10.1063/1.4913686.
Kelly, Aaron, Markland, Thomas E., Email: tmarkland@stanford.edu, & Brackbill, Nora. Accurate nonadiabatic quantum dynamics on the cheap: Making the most of mean field theory with master equations. United States. doi:10.1063/1.4913686.
Kelly, Aaron, Markland, Thomas E., Email: tmarkland@stanford.edu, and Brackbill, Nora. 2015.
"Accurate nonadiabatic quantum dynamics on the cheap: Making the most of mean field theory with master equations". United States.
doi:10.1063/1.4913686.
@article{osti_22416206,
title = {Accurate nonadiabatic quantum dynamics on the cheap: Making the most of mean field theory with master equations},
author = {Kelly, Aaron and Markland, Thomas E., Email: tmarkland@stanford.edu and Brackbill, Nora},
abstractNote = {In this article, we show how Ehrenfest mean field theory can be made both a more accurate and efficient method to treat nonadiabatic quantum dynamics by combining it with the generalized quantum master equation framework. The resulting mean field generalized quantum master equation (MFGQME) approach is a nonperturbative and nonMarkovian theory to treat open quantum systems without any restrictions on the form of the Hamiltonian that it can be applied to. By studying relaxation dynamics in a wide range of dynamical regimes, typical of charge and energy transfer, we show that MFGQME provides a much higher accuracy than a direct application of mean field theory. In addition, these increases in accuracy are accompanied by computational speedups of between one and two orders of magnitude that become larger as the system becomes more nonadiabatic. This combination of quantumclassical theory and master equation techniques thus makes it possible to obtain the accuracy of much more computationally expensive approaches at a cost lower than even mean field dynamics, providing the ability to treat the quantum dynamics of atomistic condensed phase systems for long times.},
doi = {10.1063/1.4913686},
journal = {Journal of Chemical Physics},
number = 9,
volume = 142,
place = {United States},
year = 2015,
month = 3
}

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