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Open Quantum Systems with Kadanoff-Baym Equations

Nuclear Theory 2024-03-25 v4 High Energy Physics - Phenomenology Quantum Physics

Abstract

We study the temporal evolution of quantum mechanical fermionic particles exhibiting one bound state within a one-dimensional attractive square-well potential in a heat bath of bosonic particles. For this open quantum system we formulate the non-equilibrium Kadanoff-Baym equations for the system particles by taking the interactions to be elastic 2-2 scatterings with the heat-bath particles. The corresponding spatially imhomogeneous integro-differential equations for the one-particle Greens's function are solved numerically. We demonstrate how the system particles equilibrate and thermalize with the heat bath and how the off-diagonal elements of the density matrix, expressed in the one-particle energy eigenbasis, decohere, so that only the diagonal entries, i.e. the occupation numbers, survive. In addition, the time evolution of the (retarded) Green's function also determines the spectral properties of the various one-particle quantum states.

Keywords

Cite

@article{arxiv.2308.07659,
  title  = {Open Quantum Systems with Kadanoff-Baym Equations},
  author = {Tim Neidig and Jan Rais and Marcus Bleicher and Hendrik van Hees and Carsten Greiner},
  journal= {arXiv preprint arXiv:2308.07659},
  year   = {2024}
}

Comments

6 pages, 3 figures, accepted in Physics Letters B

R2 v1 2026-06-28T11:55:54.130Z