SAMOP 2023 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

Q: Fachverband Quantenoptik und Photonik

Q 7: Poster I

Q 7.20: Poster

Monday, March 6, 2023, 16:30–19:00, Empore Lichthof

Collective radiative effects in nanofiber-coupled atomic ensembles: From timed Dicke states to full inversion — •Christian Liedl, Felix Tebbenjohanns, Constanze Bach, Sebastian Pucher, Arno Rauschenbeutel, and Philipp Schneeweiss — Department of Physics, Humboldt-Universität zu Berlin, 10099 Berlin, Germany

Dicke superradiance is a hallmark effect in quantum optics. There, an ensemble of initially excited atoms can emit a burst of light due to spontaneous phase locking of the atomic dipoles during their decay. In order to observe this phenomenon, the atoms are typically placed in close vicinity of each other. In contrast, here, we study superradiance using macroscopically separated atoms. Each atom is almost unidirectionally coupled to the nanofiber-guided mode, allowing us to describe the dynamics using a cascaded interaction model. In our experiment, we coherently invert up to 1000 atoms and study their decay dynamics. We analyze the role of coherent forward scattering over the whole parameter regime, from weak excitation to almost full inversion. We observe superradiant burst dynamics and find a characteristic threshold behavior. Finally, we find that the superradiant burst has a random phase with respect to the excitation laser. This confirms that the build-up of coherence during the decay indeed stems from spontaneous phase locking of the atoms, which lies at the heart of superradiant.