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.

In an array of one-dimensional traps, we create impurities of K atoms immersed in reservoir of Rb atoms. The impurities are first localized by an external species-selective potential and then suddenly freed: their subsequent dynamics exhibits "breathing" oscillations, due to a weaker confining potential. We find that the amplitude of these oscillations is reduced when increasing the strength of the impurity-reservoir interaction, irrespective of its sign. We interpret our data with a polaric mass shift model derived following Feynman variational approach.

J. Catani et al.
Quantum dynamics of impurities in a one-dimensional Bose gas
Phys. Rev. A 85, 023623 (2012)

K/Rb people

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

K/Rb contacts

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

Francesco Minardi
(minardi@lens.unifi.it)

K/Rb funding

PRIN2010-2011
EU FP7 EQuaM
  Progetto Premiale 2013 ABnanotech