Relationship between population dynamics and the selfenergy in driven nonequilibrium systems
We compare the decay rates of excited populations directly calculated within a Keldysh formalism to the equation of motion of the population itself for a HubbardHolstein model in two dimensions. While it is true that these two approaches must give the same answer, it is common to make a number of simplifying assumptions, within the differential equation for the populations, that allows one to interpret the decay in terms of hot electrons interacting with a phonon bath. Furthermore, we show how care must be taken to ensure an accurate treatment of the equation of motion for the populations due to the fact that there are identities that require cancellations of terms that naively look like they contribute to the decay rates. In particular, the average time dependence of the Green's functions and selfenergies plays a pivotal role in determining these decay rates.
 Authors:

^{[1]};
^{[2]}
 North Carolina State Univ., Raleigh, NC (United States). Dept. of Physics
 Georgetown Univ., Washington, DC (United States). Dept. of Physics
 Publication Date:
 Grant/Contract Number:
 FG0208ER46542; AC0205CH11231
 Type:
 Accepted Manuscript
 Journal Name:
 Entropy
 Additional Journal Information:
 Journal Volume: 18; Journal Issue: 5; Journal ID: ISSN 10994300
 Publisher:
 MDPI
 Research Org:
 Georgetown Univ., Washington, DC (United States)
 Sponsoring Org:
 USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC22)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; population dynamics; nonequilibrium Keldysh; scattering integrals; field theory
 OSTI Identifier:
 1287497
Kemper, Alexander F., and Freericks, James K.. Relationship between population dynamics and the selfenergy in driven nonequilibrium systems. United States: N. p.,
Web. doi:10.3390/e18050180.
Kemper, Alexander F., & Freericks, James K.. Relationship between population dynamics and the selfenergy in driven nonequilibrium systems. United States. doi:10.3390/e18050180.
Kemper, Alexander F., and Freericks, James K.. 2016.
"Relationship between population dynamics and the selfenergy in driven nonequilibrium systems". United States.
doi:10.3390/e18050180. https://www.osti.gov/servlets/purl/1287497.
@article{osti_1287497,
title = {Relationship between population dynamics and the selfenergy in driven nonequilibrium systems},
author = {Kemper, Alexander F. and Freericks, James K.},
abstractNote = {We compare the decay rates of excited populations directly calculated within a Keldysh formalism to the equation of motion of the population itself for a HubbardHolstein model in two dimensions. While it is true that these two approaches must give the same answer, it is common to make a number of simplifying assumptions, within the differential equation for the populations, that allows one to interpret the decay in terms of hot electrons interacting with a phonon bath. Furthermore, we show how care must be taken to ensure an accurate treatment of the equation of motion for the populations due to the fact that there are identities that require cancellations of terms that naively look like they contribute to the decay rates. In particular, the average time dependence of the Green's functions and selfenergies plays a pivotal role in determining these decay rates.},
doi = {10.3390/e18050180},
journal = {Entropy},
number = 5,
volume = 18,
place = {United States},
year = {2016},
month = {5}
}