Erlangen 2022 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 20: Quantum Gases I
Q 20.1: Poster
Dienstag, 15. März 2022, 16:30–18:30, P
Dissipative time crystals in an atom-cavity system — •Phatthamon Kongkhambut1, Hans Keßler1, Jim Skulte1,2, Ludwig Mathey1,2, Jayson G. Cosme3, and Andreas Hemmerich1,2 — 1Institut für Laser-Physik, Universität Hamburg — 2The Hamburg Center for Ultrafast Imaging — 3National Institute of Physics, University of the Philippines
We are experimentally exploring the light-matter interaction of a Bose-Einstein condensate (BEC) with a single light mode of an ultra-high finesse optical cavity. The key feature of our cavity is the small field decay rate (κ/2π = 4.5kHz), which is in the order of the recoil frequency (ωrec/2π = 3.6kHz). This leads to a unique situation where cavity field evolves with the same timescale as the atomic distribution. If the system is pumped with a steady state light field, red detuned with respect to the atomic resonance, the Dicke model is implemented. Starting in this self-ordered density wave phase and modulating the amplitude of the pump field, we observe a dissipative discrete time crystal, whose signature is a robust subharmonic oscillation between two symmetry-broken states [1]. Modulation of the phase of the pump field give rise to an incommensurate time crystalline behaviour [2-3]. For a blue-detuned pump light with respect to the atomic resonance, we propose an experimental realization of limit cycles. Since the model describing the system is time-independent, the emergence of a limit cycle phase heralds the breaking of continuous time-translation symmetry. [1] H. Keßler et al., PRL, 127, 043602 (2021). [2] J. G. Cosme et al., PRA 100, 053615 (2019). [3] P. Kongkhambut et al., arXiv:2108.11113.