Contact Measurements on Atomic BEC

ORAL

Abstract

For ultracold fermions, a powerful set of universal relations, centered on a quantity called the contact, connects the strength of short-range two-body correlations to the thermodynamics of a many-body system with zero-range interactions [1]. An interesting question is whether these ideas and the concept of the contact can be extended to bosons, where issues include the decreasing stability of BECs with increasing repulsive interactions and the possibility of three-body interactions. We present measurements of the contact, using RF spectroscopy, for an $^{85}$Rb atomic Bose-Einstein condensate (BEC) near a Feshbach resonance. To connect our measurements of the contact to three-body interactions, we located an Efimov resonance in $^{85}$Rb atoms with loss measurements and thus determine the three-body interaction parameter. \\[4pt] [1] S. Tan, Ann. Phys. {\bf323}, 2971 (2008)\\[0pt] [2] E. Braaten, D. Kang, and L. Platter, Phys. Rev. Lett. {\bf106}, 153005 (2011).

*This work is supported by the NSF, ONR, and NIST.

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Authors

  • Philip Makotyn

    • JILA

  • Catherine Klauss

    • JILA

  • Robert Wild

    • None

  • Eric Cornell

    • JILA, National Institute of Standards and Technology and University of Colorado
    • JILA

  • Deborah Jin

    • JILA, National Institute of Standards and Technology and University of Colorado; Physics Department, University of Colorado, Boulder, Colorado 80309
    • JILA, NIST, and University of Colorado, Boulder
    • JILA
    • JILA/University of Colorado