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Accueil > Événements > Séminaires 2016

Disorder physics with tunable interactions : experiments with ultracold 39K

Steven Lepoutre

5 février 2016 à 11 heures

During this seminar, I will present the experiments performed in the
team “Disordered quantum gases with tunable interaction” at Laboratoire Charles Fabry (Palaiseau). We implemented an all-optical sequence to obtain Bose-Einstein condensates of 39K, a species with tunable interactions between atoms thanks to accessible Feshbach resonances. By tuning to attractive interactions, we created solitonic matterwaves (solitons) propagating in a one-dimensional (1D) waveguide, and studied their diffusion by a random potential applied using a laser speckle. We also observed similar processes with an ideal 1D Bose gas obtained when the interactions are cancelled. While diffusion of an ideal 1D Bose gas leads to Anderson localization (AL) of the matterwave, in the case of a soliton, the existence of an attractive interatomic potential is expected to alter localization. The interplay between localization phenomena and nonlinear processes such as interactions is the subject of intense research in various fields of physics. I will present preliminary results of measurements recently obtained.