Feedback Control of Trapped Coherent Atomic Ensembles

Thomas Vanderbruggen (1) , Ralf Kohlhaas (1) , Andrea Bertoldi (2, 1) , Simon Bernon (1) , Alain Aspect (1) , Arnaud Landragin (3) , Philippe Bouyer (2, 1)

1 Laboratoire Charles Fabry / Optique atomique
2 lp2n-02,lp2n-11
3 LNE - SYRTE - Laboratoire national de métrologie et d'essais - Systèmes de Référence Temps-Espace

We demonstrate how to use feedback to control the internal states of trapped coherent ensembles of two-level atoms, and to protect a superposition state against the decoherence induced by a collective noise. Our feedback scheme is based on weak optical measurements with negligible backaction followed by coherent microwave manipulations. The efficiency of the feedback system is studied for a simple binary noise model and characterized in terms of the trade-off between information retrieval and destructivity from the optical probe. We also demonstrate the correction of more general types of collective noise. This technique can be used for the operation of atomic interferometers beyond the standard Ramsey scheme, opening the way towards improved atomic sensors.

Domains: Atomic Physics [physics.atom-ph]; Optics [physics.optics]

Thomas Vanderbruggen, Ralf Kohlhaas, Andrea Bertoldi, Simon Bernon, Alain Aspect, et al.. Feedback Control of Trapped Coherent Atomic Ensembles. Physical Review Letters, 2013, 110 (21), pp.210503. ⟨10.1103/PhysRevLett.110.210503⟩. ⟨hal-00995374⟩