Harmonic and Subharmonic Association and Dissociation of Universal Dimers in a Thermal Gas

Abstract

In a gas of ultracold atoms whose scattering length is controlled by a magnetic Feshbach resonance, atoms can be associated into universal dimers by an oscillating magnetic field. In addition to the harmonic resonance with frequency near that determined by the dimer binding energy, there is a subharmonic resonance with half that frequency. If the thermal gas contains dimers, they can be dissociated into unbound atoms by the oscillating magnetic field. We show that the transition rates for association and dissociation can be calculated by treating the oscillating magnetic field as a sinusoidal time-dependent perturbation proportional to the contact operator. Many-body effects are taken into account through transition matrix elements of the contact operator. We calculate both the harmonic and subharmonic transition rates analytically for association in a thermal gas of atoms and dissociation in a thermal gas of dimers.

26 pages, 4 figures

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Cited by in corpus (4)

• Improved characterization of Feshbach resonances and interaction potentials between ${}^{23}$Na and ${}^{87}$Rb atoms
• Optically trapped Feshbach molecules of fermionic 161Dy and 40K
• Observation of coherent oscillations in association of dimers from a thermal gas of ultracold atoms
• Resonant Floquet Scattering of Ultracold Atoms