Open system dynamics in interacting quantum field theories

Fuente: arXiv
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Main Authors: Bowen, Brenden, Agarwal, Nishant, Kamal, Archana
Format: Preprint
Published: 2024
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author Bowen, Brenden
Agarwal, Nishant
Kamal, Archana
author_facet Bowen, Brenden
Agarwal, Nishant
Kamal, Archana
contents A quantum system that interacts with an environment generally undergoes nonunitary evolution described by a non-Markovian or Markovian master equation. In this paper, we construct the non-Markovian Redfield master equation for a quantum scalar field that interacts with a second field through a bilinear or nonlinear interaction on a Minkowski background. We use the resulting master equation to set up coupled differential equations that can be solved to obtain the equal-time two-point function of the system field. We show how the equations simplify under various approximations including the Markovian limit and argue that the Redfield equation-based solution provides a perturbative resummation to the standard second-order Dyson series result. For the bilinear interaction, we explicitly show that the Redfield solution is closer to the exact solution compared to the perturbation theory-based one. Further, the environment correlation function is oscillatory and nondecaying in this case, making the Markovian master equation a poor approximation. For the nonlinear interaction, on the other hand, the environment correlation function is sharply peaked and the Redfield solution matches that obtained using a Markovian master equation in the late-time limit.
format Preprint
id arxiv_https___arxiv_org_abs_2403_18907
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Open system dynamics in interacting quantum field theories
Bowen, Brenden
Agarwal, Nishant
Kamal, Archana
High Energy Physics - Theory
Quantum Physics
A quantum system that interacts with an environment generally undergoes nonunitary evolution described by a non-Markovian or Markovian master equation. In this paper, we construct the non-Markovian Redfield master equation for a quantum scalar field that interacts with a second field through a bilinear or nonlinear interaction on a Minkowski background. We use the resulting master equation to set up coupled differential equations that can be solved to obtain the equal-time two-point function of the system field. We show how the equations simplify under various approximations including the Markovian limit and argue that the Redfield equation-based solution provides a perturbative resummation to the standard second-order Dyson series result. For the bilinear interaction, we explicitly show that the Redfield solution is closer to the exact solution compared to the perturbation theory-based one. Further, the environment correlation function is oscillatory and nondecaying in this case, making the Markovian master equation a poor approximation. For the nonlinear interaction, on the other hand, the environment correlation function is sharply peaked and the Redfield solution matches that obtained using a Markovian master equation in the late-time limit.
title Open system dynamics in interacting quantum field theories
topic High Energy Physics - Theory
Quantum Physics
url https://arxiv.org/abs/2403.18907