2009/12/26 by Matt Mackie, Catherine DeBrosse
Chemistry · Physics and Astronomy · #Atomic physics #Bose–Einstein condensate #Chemistry #Cold Atom Physics and Bose-Einstein Condensates #Dissociation (chemistry) #Feshbach resonance #Laser #Magnetic field #Molecule #Physics #Quantum #Quantum mechanics #Quantum optics and atomic interactions #Quantum, superfluid, helium dynamics #Resonance (particle physics) #cond-mat.quant-gas
paper · pdf · doi:10.1103/physreva.81.043625
10 pages, 5 figures, 82 references
arxiv created 2009/12/26 · openalex publication_date 2010/04/23 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We model combined photoassociation and Feshbach resonances in a Bose-Einstein condensate, where the shared dissociation continuum allows for quantum interference in losses from the condensate, as well as a dispersive-like shift of resonance. A seemingly oversimplified model is revisited, explaining it as based on the limit of weakly bound molecules, reinforcing it with a comparison to numerical experiments that explicitly include dissociation to noncondensate modes, comparing it against the unitarity limit on condensate losses, and lastly, checking its universal implications. In particular, for a resonant laser and an off-resonant magnetic field, these numerical experiments reveal a rate limit on condensate losses that is larger for smaller condensate densities, approaches the rate limit for magnetoassociation alone near the Feshbach resonance, and agrees best with the analytical model for low density. Comparing the analytical rate limit against the unitary limit, which is set by the size of the condensate, agreement is found only for a limited range of near-resonant magnetic fields. Finally, for a resonant magnetic field and an off-resonant laser, the analytical shift of the Feshbach resonance is found to depend on the size of the Feshbach molecule, signifying nonuniversal physics in a strongly interacting system.