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Measurement of the Zero Crossing in a Feshbach Resonance of Fermionic 6-Li

K. M. O'Hara·S. L. Hemmer·S. R. Granade·M. E. Gehm·J. E. Thomas·V. Venturi·E. Tiesinga·C. J. Williams
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Abstract

We measure a zero crossing in the scattering length of a mixture of the two lowest hyperfine states of 6-Li. To locate the zero crossing, we monitor the decrease in temperature and atom number arising from evaporation in a CO2 laser trap as a function of magnetic field B. The temperature decrease and atom loss are minimized for B=528(4) G, consistent with no evaporation. We also present preliminary calculations using potentials that have been constrained by the measured zero crossing and locate a broad Feshbach resonance at approximately 860 G, in agreement with previous theoretical predictions. In addition, our theoretical model predicts a second and much narrower Feshbach resonance near 550 G.

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K. M. O'Hara, S. L. Hemmer, S. R. Granade, M. E. Gehm, J. E. Thomas, V. Venturi, E. Tiesinga, C. J. Williams. 2002-07-30. Measurement of the Zero Crossing in a Feshbach Resonance of Fermionic 6-Li. https://doi.org/10.1103/physreva.66.041401

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