Hannover 2016 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 57: Quantum Effects: QED II

Q 57.7: Vortrag

Donnerstag, 3. März 2016, 16:15–16:30, f442

Thermodynamics and relaxation in a system of photon-mediated long-range interactions — •Stefan Schütz, Simon Balthasar Jäger, and Giovanna Morigi — Theoretische Physik, Universität des Saarlandes, D-66123 Saarbrücken, Germany

We study the steady-state properties and relaxation dynamics of atoms in the quantum field of an optical cavity and which are driven by a laser. In a semiclassical limit we show that the steady state is a thermal distribution whose temperature is solely controlled by the detuning between laser and cavity. The laser intensity, on the other hand, determines the onset of selforganized Bragg gratings. We evaluate the free energy and demonstrate that the selforganization transition is a second-order phase transition described by Landau’s model: the control field is the laser intensity and the order parameter is the cavity field amplitude. We then discuss the dynamics following a sudden quench across the phase transition, and report the observation of metastable spatial patterns, whose lifetime can be several resonator lifetimes. These metastable patterns are nonthermal and result from the interplay between the dispersive and the dissipative mechanical forces of the resonator.

[1] S. Schütz, H. Habibian, and G. Morigi, Phys. Rev. A 88, 033427 (2013)

[2] S. Schütz, S. B. Jäger, and G. Morigi, arXiv 1508.06606v1, PRA in press.

[3] S. Schütz and G. Morigi, Phys. Rev. Lett. 113, 203002 (2014)