Testing universality of Efimov physics across broad and narrow Feshbach resonances

Jacob Johansen; B. J. DeSalvo; Krutik Patel; Cheng Chin

doi:10.1038/nphys4130

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arXiv · 1612.05169

Testing universality of Efimov physics across broad and narrow Feshbach resonances

Jacob Johansen·B. J. DeSalvo·Krutik Patel·Cheng Chin

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Abstract

Efimov physics is a universal phenomenon arising in quantum three-body systems. For systems with resonant two-body interactions, Efimov predicted an infinite series of three-body bound states with geometric scaling symmetry. These Efimov states were first observed in cold Cs atoms and have since been reported in a variety of atomic systems. While theories predict non-universal behavior for narrow Feshbach resonances, experiments on Efimov resonances are so far consistent with predictions based on universal theories. Here we directly compare the Efimov spectra in a $^6$Li-$^{133}$Cs mixture near two Feshbach resonances which are very different in their resonance strengths but otherwise almost identical. Our result shows a clear dependence of the Efimov resonance positions on Feshbach resonance strength and a clear departure from the universal prediction for the narrow Feshbach resonance.

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Jacob Johansen, B. J. DeSalvo, Krutik Patel, Cheng Chin. 2016-12-15. Testing universality of Efimov physics across broad and narrow Feshbach resonances. https://doi.org/10.1038/nphys4130

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