Shortcuts to adiabaticity for trapped ultracold gases

J-F. SCHAFF; P. CAPUZZI; G. LABEYRIE; P. VIGNOLO

Sant Feliu de Guixols

Congreso; Bose-Einstein condensation 2011: Frontiers in Quantum Gases; 2011

We study, experimentally and theoretically, the controlled transfer of harmonically trapped ultracold gases between different quantum states. In particular we experimentally demonstrate a fast decompression and shift of a cold gas of non-interacting bosons as well as an interacting Bose-Einstein condensate as it would be obtained with an adiabatic process but only in a few dozens milliseconds. During the transfer the atomic sample goes through strongly out-of-equilibrium states while the external confinement is modified until the system reaches the desired stationary state. The scheme is theoretically based on the invariants of motion and scaling equations techniques and can be generalized to decompression trajectories including an arbitrary deformation of the trap.