Rostock 2019 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 20: Cold Molecules (joint session MO/A)
A 20.2: Vortrag
Mittwoch, 13. März 2019, 14:15–14:30, S HS 002 Biologie
Phase protection of Fano-Feshbach resonances — Alexander Blech1, Yuval Shagam2, Nicolas J. Hölsch2, Prerna Paliwal2, Wojciech Skomorowski1, John W. Rosenberg2, Daniel Zajfman3, Oded Heber3, •Daniel M. Reich1, Edvardas Narevicius2, and Christiane P. Koch1,2 — 1Theoretische Physik, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany — 2Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel — 3Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100, Israel
Fano-Feshbach resonances (FFR) describe the decay of a quantum system due to coupling of quantum-mechanical bound states to a continuum of scattering states. They serve as a key mechanism to controlling interactions in ultracold atomic gases. The position of FFR was shown to follow quantum chaotic statistics. In contrast, their lifetimes have so far escaped a similarly comprehensive understanding, despite the intriguing observation of spanning many orders of magnitude. We attribute this phenomenon, which has also been observed in predissociation FFR, to phase protection: For each scattering energy, there exists a phase for which the lifetime becomes infinite. Any bound state which is resonantly coupled to the scattering state with exactly this phase is phase protected. Supported by lifetime measurements of rovibrational FFR, we demonstrate that both the reduced mass and the shape of the potential can significantly influence the occurence of phase-protected resonances. Our results provide a blueprint for identifying naturally long-lived states in a decaying quantum system.