title: Association of atoms into universal dimers using an oscillating magnetic field.
abstract: In a system of ultracold atoms near a Feshbach resonance, pairs of atoms can be associated into universal dimers by an oscillating magnetic field with a frequency near that determined by the dimer binding energy. We present a simple expression for the transition rate that takes into account many-body effects through a transition matrix element of the contact. In a thermal gas, the width of the peak in the transition rate as a function of the frequency is determined by the temperature. In a dilute Bose-Einstein condensate of atoms, the width is determined by the inelastic scattering rates of a dimer with zero-energy atoms. Near an atom-dimer resonance, there is a dramatic increase in the width from inelastic atom-dimer scattering and from atom-atom-dimer recombination. The recombination contribution provides a signature for universal tetramers that are Efimov states consisting of two atoms and a dimer.
authors: Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA.
authors: Christian
authors: C
authors: Langmack
authors: Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA.
authors: D Hudson
authors: DH
authors: Smith
authors: Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA.
authors: Eric
authors: E
authors: Braaten