Considering the hurdles of experiments with more than one atomic species, the temptation arises of rephrasing Arthur L. Schawlow: "Double-species Bose-Einstein condensates are condensates with one species too many". We think otherwise. Quantum mixtures allow the investigation of a wealth of genuinely quantum phenomena: mixed phases of superfluids and Mott insulators, impurities and polarons, chemistry at zero-temperature.

A K/Rb double BEC

We have realized a double-species Bose-Einstein Condensate of 87Rb-41K both in the F=2, mF=2 hyperfine states. The preparation of the superfluid mixtures involves different cooling stages. After a double-MOT phase we transfer the mixture in a magnetic quadrupole field where Rb is evaporated by a microwave radiation resonant on the (F=2, mF=2) - (F=1, mF=1) transition while K is sympathetically cooled by thermal contact with Rb. When the temperature is low enough, we transfer the mixture in a crossed optical trap through an intermediate stage of a hybrid magneto-optical trapping potential. The last stage of cooling is performed by pure optical evaporation in the crossed optical potential. At the end of our typical experimental runs we produce pure condensates of 6×104 atoms for both atomic species.

K/Rb people

Alessia Burchianti
Research fellow
Chiara D'Errico
Permanent researcher
Chiara Fort
Permanent researcher
Massimo Inguscio
Permanent researcher
Francesco Minardi
Permanent researcher
Former members:
Giovanni Barontini
Jacopo Catani
Stefano Conclave
Luigi De Sarlo
Giacomo Lamporesi
Paolo Maioli
Sara Rosi
Devang S. Naik
Gregor Thalhammer

K/Rb contacts

For further information, request of material, job opportunities, please contact:

Francesco Minardi

K/Rb funding

  Progetto Premiale 2013 ABnanotech