In this talk, I propose to focus on two recent experimental results of our team obtained by shaking a Bose Einstein condensate in an optical lattice:
1) In the first part, I will focus the discussion on the production of s-wave scattering halos from collisions between the momentum components of a Bose–Einstein condensate released from an optical lattice which provides an interesting example of matter-wave duality. I will report on the methods we have developed to engineer those halos . More generally, we will explain a strategy to produce arbitrary quantum states using optimal control theory .
2) In the second part, I will focus on quasi-resonant modulation of the lattice depth to observe a quantum chaos transport mechanism called chaos-assisted tunneling. Under such a modulation, the classical phase space exhibits stable islands surrounded by a large chaotic sea. The coupling between islands is mediated by delocalized Floquet states that spread over the chaotic sea. As a result, the transport between the islands exhibit sharp resonances where the tunneling rate varies by orders of magnitude over a short range of parameters. We experimentally demonstrate and characterize these resonances for the first time in a quantum system. This opens the way to new kinds of quantum simulations with long-range transport [3,4].
 G. Chatelain, N. Dupont, M. Arnal, B. Brunaud, J. Billy, B. Peaudecerf, P. Schlagheck and D. Guéry-Odelin, New Journal of Physics 22, 123032 (2020).
 N. Dupont et al., in preparation
 M. Arnal, G. Chatelain, M. Martinez, N. Dupont, O. Giraud, D. Ullmo, B. Georgeot, G. Lemarié, J. Billy and D. Guéry-Odelin, Science Advances 6, eabc4486 (2020).
 M. Martinez, O. Giraud, D. Ullmo, J. Billy, D. Guéry-Odelin, B. Georgeot, and G. Lemarié, arXiv:2011.02557v1 [quant-ph]
Pubblicato Venerdì, 14 Maggio, 2021 - 09:42 | ultima modifica Venerdì, 14 Maggio, 2021 - 11:12