Feshbach resonances, weakly bound molecular states, and coupled-channel potentials for cesium at high magnetic fields
Authors: Berninger M., Zenesini A., Huang B., Harm W., Nagerl, H.-C., Ferlaino F., Grimm R., Julienne P.S., Hutson J.M.,
Autors Affiliation: Univ Innsbruck, Inst Expt Phys, A-6020 Innsbruck, Austria; Univ Innsbruck, Zentrum Quantenphys, A-6020 Innsbruck, Austria; Austrian Acad Sci, Inst Quantenopt & Quanteninformat, A-6020 Innsbruck, Austria; NIST, Joint Quantum Inst, Gaithersburg, MD 20899 USA; Univ Maryland, Gaithersburg, MD 20899 USA; Univ Durham, Dept Chem, JQC Durham Newcastle, Durham DH1 3LE, England
Abstract: We explore the scattering properties of ultracold ground-state Cs atoms at magnetic fields between 450 G (45 mT) and 1000 G. We identify 17 previously unreported Feshbach resonances, including two very broad ones near 549 and 787 G. We measure the binding energies of several different dimer states by magnetic field modulation spectroscopy. We use least-squares fitting to these experimental results, together with previous measurements at lower field, to determine a six-parameter model of the long-range interaction potential, designated M2012. Coupled-channels calculations using M2012 provide an accurate mapping between the s-wave scattering length and the magnetic field over the entire range of fields considered. This mapping is crucial for experiments that rely on precise tuning of the scattering length, such as those on Efimov physics.
Journal/Review: PHYSICAL REVIEW A
Volume: 87(3) Pages from: 032517-1 to: 032517-17
KeyWords: BOSE-EINSTEIN CONDENSATION; LONG-RANGE POTENTIALS; LOG-DERIVATIVE METHOD; RELAXATION RATES; ULTRACOLD ATOMS; ENERGY-LEVELS; METAL ATOMS; QUANTUM GAS; SCATTERING; COLLISIONSDOI: 10.1103/PhysRevA.87.032517