Precise characterization of Li-6 Feshbach resonances using trap-sideband-resolved RF spectroscopy of weakly bound molecules

Zuern, G.; Lompe, T.; Wenz, A. N.; Jochim, S.; Julienne, P. S.; Hutson, J. M.

Abstract

We perform radio-frequency dissociation spectroscopy of weakly bound 6Li2 Feshbach molecules using low-density samples of about 30 molecules in an optical dipole trap. Combined with a high magnetic field stability, this allows us to resolve the discrete trap levels in the radio-frequency dissociation spectra. This novel technique allows the binding energy of Feshbach molecules to be determined with unprecedented precision. We use these measurements as an input for a fit to the 6Li scattering potential using coupled-channel calculations. From this new potential, we determine the pole positions of the broad 6Li Feshbach resonances with an accuracy better than 7×10-4 of the resonance widths. This eliminates the dominant uncertainty for current precision measurements of the equation of state of strongly interacting Fermi gases. As an important consequence, our results imply a corrected value for the Bertsch parameter ξ measured by Ku et al. [ Science 335 563 (2012)], which is ξ=0.370(5)(8).

Citation

Zuern, G., Lompe, T., Wenz, A. N., Jochim, S., Julienne, P. S., & Hutson, J. M. (2013). Precise characterization of Li-6 Feshbach resonances using trap-sideband-resolved RF spectroscopy of weakly bound molecules. Physical Review Letters, 110(13), Article 135301. https://doi.org/10.1103/physrevlett.110.135301

• Journal Article Type: Article
• Publication Date: Jan 1, 2013
• Deposit Date: Jun 19, 2013
• Publicly Available Date: Jun 28, 2013
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 110
• Issue: 13
• Article Number: 135301
• DOI: https://doi.org/10.1103/physrevlett.110.135301
• Public URL: https://durham-repository.worktribe.com/output/1473735