Seminarium "Coherence-Correlations-Complexity" (KFT, PWr)
Platforma Zoom
Phase space and entropy dynamics of a single phonon mode coupled to a two-level system driven by optical excitation
Thilo Hahn
Institut für Festkörpertheorie, University of Münster
The seminar will be broadcast on the Zoom platform (the link will be made available to interested persons after prior contact at ).
Abstract:
Entropy is a fundamental concept in physics. While under non-equilibrium conditions the second law of thermodynamics prohibits the decrease of the entropy in a closed system, the entropy of a subsystem interacting with its environment may decrease [1]. We consider a two-level system (TLS) coupled to a single phonon mode via the pure dephasing coupling and investigate the phonon dynamics in phase space in terms of the Wigner function after ultrafast optical excitation of the TLS [2]. In particular, an excited state decay leads to non-trivial phonon states. Their Wigner function is directly connected to the linear Entropy whose dynamics will be discussed [3]. Exemplarily, the decay of a coherent state and a Schrödinger cat state show interesting entropy and phase space
behavior.
[1] J. Eisert, M. Kramer and M.B. Plenio, Rev. Mod. Phys 82, 277 (2010).
[2] T. Hahn, D. Groll, T. Kuhn and D. Wigger, Phys. Rev. B 100, 5 (2019).
[3] T. Hahn, D. Wigger and T. Kuhn, Entropy 22, 286 (2020).
