Hannover 2013 – scientific programme
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A: Fachverband Atomphysik
A 26: Ultra-cold atoms, ions and BEC V (with Q)
A 26.7: Talk
Wednesday, March 20, 2013, 15:45–16:00, B 302
Photoassociation near the intercombination line of 40Ca — •Max Kahmann1, Oliver Appel1, Eberhard Tiemann2, Fritz Riehle1, and Uwe Sterr1 — 1Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Welfengarten 1, 30167 Hannover — 2Institut für Quatenoptik, Universität Hannover, Welfengarten 1, 30167 Hannover
We have measured for the first time photoassociation resonances in the narrow-line system 1S0 + 3P1. We use about 105 calcium atoms that are trapped and evaporatively cooled to about 1 µK in a crossed optical dipole trap at a density of 1013 cm−3. Precisely tunable laser light is produced by offset locking a diode laser to a laser which is resonant to the atomic line. The light is applied for typically 1 s to the trapped atoms and the trap loss is observed from absorption images of the atomic cloud. In a range of up to 25 GHz below the asymptote we have observed 6 photoassociation resonances in the two molecular potentials Ω = 0 and Ω = 1 correlating to the 3P1 + 1S0 asymptote. In both the Ω = 0 and 1 excited states we observe a Zeeman splitting.
A theoretical model was developed in order to describe the Zeeman splitting and the energy of the bound molecular states in both potentials. The data helps to improve our knowledge of the molecular parameters and the dispersion coefficients and allows the use of low-loss optical Feshbach resonances to manipulate the atomic scattering length.