Presenter: Denis Boiron; Laboratoire Charles Fabry, Institut d'Optique Graduate School, France
Host: I. Fuentes Guridi
Where: Josef-Stefan HS, Boltzmanngasse 5, 3rd floor, 1090 Wien
I will present an atomic analogue of the 1987 experiment of Hong, Ou and Mandel: two photons impinging each on a different imput port of a beamsplitter always emerge in the same output port if they are indistinguishable. This is a simple yet very illustrative two-particle effect not explainable by classical means. In our experiment, starting with a Bose-Einstein condensate of metastable helium, we have produced pairs of atoms by a four-wave mixing process. These atoms are manipulated by laser beams in a Bragg diffraction configuration to mimic mirrors and beam-splitters. The coincidence measurement at the output port of the beam-splitter is performed with a single-atom 3D resolved detector. Varying the indistinguishability, we have observed a dip in the coincidence count whose visibility is only compatible with quantum theory, as in the 1987 experiment.