Mattias Gustavsson
University of Innsbruck
Tuesday, April 29, 2008
2:00 pm in SPL 52
Matter wave interference due to interactions and an ultracold gas of deeply bound Cs2 molecules
Abstract: We observe matter wave interference which is driven by interactions. When a BEC in a lattice potential undergoes Bloch oscillations at non-zero scattering length, the condensate quickly dephases and develops an interference pattern inside the first Brillouin zone. The dephasing is coherent and can be controlled and reversed by applying a suitable external potential. When tuning the scattering length to zero, dephasing is suppressed and we can follow more than 20000 oscillations over 12 s.
We also demonstrate STIRAP transfer of Feshbach molecules produced from a BEC into the v=73 vibrational level of the singlet potential, a state with 30 THz binding energy. The transfer efficiency is 80%. Our results show that a BEC of ro-vibrational ground state molecules is within reach.