Spin self-rephasing and very long coherence times in trapped atomic ensembles

Xavier Alauze, Alexis Bonnin, Franck Pereira dos Santos +4 more

C. W. Chou, D. Felinto, Hugues de Riedmatten +2 more

Christian Deutsch, F. Ramírez-Martínez, Clément Lacroûte +7 more

We perform Ramsey spectroscopy on the ground state of ultracold 87Rb atoms magnetically trapped on a chip in the Knudsen regime. Field inhomogeneities over the sample should limit the 1/e contrast decay time to about 3 s, while decay times of 58 ± 12 s are actually observed. We explain this surprising result by a spin self-rephasing mechanism induced by the identical spin rotation effect originating from particle indistinguishability. We propose a theory of this synchronization mechanism and obtain good agreement with the experimental observations. The effect is general and may appear in other physical systems.

P. Rosenbusch

We perform Ramsey spectroscopy on the ground state of ultra-cold 87Rb atoms magnetically trapped on a chip in the Knudsen regime. Field inhomogeneities over the sample should limit the 1/e contrast decay time to about 3 s, while decay times of 58 ± 12 s are actually observed. We explain this surprising result by a spin self-rephasing mechanism induced by the identical spin rotation effect originating from the exchange interaction. We propose a theory of this synchronization mechanism and obtain good agreement with the experimental observations. The effect is general and may appear in other physical systems.

M. V. Egorov, R. P. Anderson, Valentin Ivannikov +4 more

Mean-field induced self-rephasing and the synchronized application of spin echo allow us to preserve coherence of an interacting Bose-Einstein condensate for a long time (> 4 s) in a trapped Ramsey interferometer on an atom chip.

Joshua Nunn