2006/07/04 by Silke Ospelkaus, S. Ospelkaus, C. Ospelkaus +5 · 167 citations
Physics and Astronomy · #Atomic physics #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Degenerate energy levels #Fermi Gamma-ray Space Telescope #Feshbach resonance #Heteronuclear molecule #Mean field theory #Molecule #Phase (matter) #Phase diagram #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Quantum, superfluid, helium dynamics #Resonance (particle physics) #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevlett.97.120403
published in Physical Review Letters 97(12), 120403 (American Physical Society) · 4 pages, 4 figures
arxiv created 2006/07/04 · openalex publication_date 2006/09/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We demonstrate tuning of interactions between fermionic 40K and bosonic 87Rb atoms by Feshbach resonances and access the complete phase diagram of the harmonically trapped mixture from phase separation to collapse. On the attractive side of the resonance, we observe a strongly enhanced mean-field energy of the condensate due to the mutual mean-field confinement, predicted by a Thomas-Fermi model. As we increase heteronuclear interactions beyond a threshold, we observe an induced collapse of the mixture. On the repulsive side of the resonance, we observe vertical phase separation of the mixture in the presence of the gravitational force, thus entering a completely unexplored part of the phase diagram of the mixture. In addition, we identify the 515 G resonance as p wave by its characteristic doublet structure.