Bonn 2025 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 11: Poster – Cold Atoms and Molecules, Matter Waves (joint session Q/A/MO)
A 11.59: Poster
Dienstag, 11. März 2025, 14:00–16:00, Tent
An experimental study of the heating of laser-cooled atoms in a nanofiber-based two-color trap — •Antoine Glicenstein, Riccardo Pennetta, Daniel Lechner, Jürgen Volz, Philipp Schneeweiss, and Arno Rauschenbeutel — Department of Physics, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
The lifetime of atoms in nanofiber-based optical traps is significantly smaller than in comparable free-space traps. This experimental observation has been made for different types of trapped atoms such as Cesium or Rubidium, and the mechanical motion of the nanofiber has been proposed to be the major factor behind the excess heating [1]. By analyzing the polarization fluctuations of light transmitted through the nanofiber, we observe the nanofiber’s fundamental torsional mode [2], which exhibits a Q-factor of up to 107 and a resonance frequency close to the trapping frequencies. In order to study its potential influence on the atoms’ lifetime, a piezo actuator is integrated into the nanofiber holder. While we successfully implemented feedback cooling to suppress the torsional motion and actively drove the torsional mode, neither approach resulted in a significant modification of the lifetime, indicating that the torsional mode is irrelevant for the heating rate of trapped atoms. Our research now shifts to investigating flexural modes, which are theoretically predicted to contribute most strongly to the heating [1] but are experimentally more challenging to address.
[1] Hümmer et al., PRX 9, 041034 (2019) [2] Tebbenjohanns et al., PRA 108, L031101 (2023)
Keywords: cold atoms; nanofiber; trapping; optomechanics