Fattori, Marco

Date: Monday, September 5, 2016
Time: 15:30
Place: ETH Zurich, Hönggerberg, HPF G 6
Host: Tilman Esslinger / Manuele Landini

Ultra-cold atoms with tunable interactions in a double well potential: a new system for precision measurements and fundamental physics tests

Marco Fattori
University of Florence, Italy

We report on the recent realization of an ultra-stable double well potential for ultra-cold bosonic atoms where inter-particle interactions can be finely tuned using a magnetic Feshbach resonance. For negative values of the collisional scattering length we explore the occurrence of a quantum phase transition where the parity symmetry of the system is broken. In addition we observe hysteresis in the disordered part of the phase diagram and we report on the promising perspectives for the generation of Schroedinger cat states with large atom number across the critical point. For positive values of the scattering length we study the crossing over from Rabi to Josephson in a tunneling bosonic Josephson junction and the slowing down of the oscillation frequencies in correspondence of Macroscopic Quantum Self Trapping. Finally for negligible values of the scattering length we prove the operation of a Mach-Zender interferometer with trapped condensed atoms. The record coherence time of almost half a second open promising perspectives for measurements of gravity and electromagnetic fields with high precision and high spatial resolution.