Studying superfluid phenomena with weakly linked Bose-Einstein condensates to realize new quantum interferometric devices.

Two (or multiple) weakly linked Bose-Einstein condensates provide an ideal setup for the study of superfluid phenomena as well as the construction of quantum interferometric devices. Condensates of alkali atoms are indeed fully superfluid, allowing to observe Josephson physics, and have in addition a very large condensate fraction, which provides the high degree of coherence required for interferometry. Moreover, the finely tunable interactions enforce on the one hand the stability of the superfluid and on the other hand the creation of entangled states providing quantum enhanced interferometric precision.

We first characterize the superfluid properties of these systems using the current-phase relation, discussing novel features appearing in the current-phase relation of ultracold dilute bosons with respect to liquid helium or superconductors, and propose a possible measurement with an atomic Bose-Einstein condensates trapped inside a double-well. We then turn to quantum interferometric applications, proposing alternative schemes to the Mach-Zehnder to be implemented in a double-well, and finally consider a multimode interferometer implemented inside an optical lattice (image by Max-Planck-Institut für Gravitationsphysik).

For further informations, please contact Dr. Marco Fattori.