Condensed Matter Physics, 2012, vol. 15, No. 4, p. 43004:19
DOI:10.5488/CMP.15.43004
arXiv:1212.6135
Title:
Entropy production in open quantum systems: exactly solvable qubit models
Author(s):

V.G. Morozov
(Moscow State Technical University of Radioengineering, Electronics, and Automation, Vernadsky Prospect 78, 119454 Moscow, Russia)
,


G. Röpke
(University of Rostock, FB Physik, Universit\""atsplatz 3, D18051 Rostock, Germany)

We present analytical results for the timedependent information entropy in exactly solvable twostate (qubit) models. The first model describes dephasing (decoherence) in a qubit coupled to a bath of harmonic oscillators. The entropy production for this model in the regimes of "complete" and "incomplete" decoherence is discussed. As another example, we consider the damped JaynesCummings model describing a spontaneous decay of a twolevel system into the field vacuum. It is shown that, for all strengths of coupling, the open system passes through the mixed state with the maximum information entropy.
Key words:
information entropy, open quantum systems, qubit models, decoherence, quantum entanglement
PACS:
03.65.Ud, 03.65.Yz
