Observation of atom pairs in spontaneous four wave mixing of two colliding Bose-Einstein Condensates

Aurélien Perrin (1) , Hong Chang (1) , Valentina Krachmalnicoff (1) , Martijn Schellekens (1) , Denis Boiron (1) , Alain Aspect (1) , Christoph I Westbrook (1)

1 laboratoire Charles Fabry de l'Institut d'Optique / Optique atomique

We study atom scattering from two colliding Bose-Einstein condensates using a position sensitive, time resolved, single atom detector. In analogy to quantum optics, the process can also be thought of as spontaneous, degenerate four wave mixing of de Broglie waves. We find a clear correlation between atoms with opposite momenta, demonstrating pair production in the scattering process. We also observe a Hanbury Brown and Twiss correlation for collinear momenta, which permits an independent measurement of the size of the pair production source and thus the size of the spatial mode. The back to back pairs occupy very nearly two oppositely directed spatial modes, a promising feature for future quantum optics experiments.

Mots clés: correlated atom pairs; Hanbury Brown-Twiss effect

Domaines: Physique Quantique [quant-ph]; Autre [cond-mat.other]

Aurélien Perrin, Hong Chang, Valentina Krachmalnicoff, Martijn Schellekens, Denis Boiron, et al.. Observation of atom pairs in spontaneous four wave mixing of two colliding Bose-Einstein Condensates. Physical Review Letters, 2007, 99 (15), pp.150405. ⟨10.1103/PhysRevLett.99.150405⟩. ⟨hal-00142991v3⟩