Experimental study of collective light scattering in dense cold atomic ensembles

ORAL

Abstract

We study the collective scattering of near-resonant light by a dense cloud of cold atoms.

In such an ensemble, the interactions between light-induced dipoles produce nonlinearities potentially useful to deterministically generate non-classical states of light, a resources for quantum information processing. Besides, this system holds fundamental interest as an example of a many-body driven dissipative spin model.

We have built a new-generation experiment, where we load up to 15000 87Rb atoms in an optical tweezer with a variable beam waist.The resulting cloud has a length up to ∼ 80λ and a sub-λ width (λ = 780.2 nm). This geometry, sharing similarities with cavity and waveguide QED systems, displays effects such as super-and sub-radiance resulting from the interactions between dipoles.

We observe strong driven superradiance and using spatial filtering we isolate the free-space super-radiant emission modes and are now measuring their temporal and spatial correlations properties. We are also preparing the excitation of a subradiant spin wave, for its potential as a quantum memory.

Presenters

  • Guillaume Tremblier

    • Université Paris Saclay

Authors

  • Guillaume Tremblier

    • Université Paris Saclay
  • Adrien Gavalda

    • Institut optique
  • Martin Poitrinal

    • Université Paris Saclay
  • Sara Pancaldi

    • Institut optique
  • Igor Ferrier-Barbut

    • CNRS
  • Antoine Browaeys

    • CNRS
    • IOGS
    • Institut d'Optique, CNRS