Letter | Published:

Testing universality of Efimov physics across broad and narrow Feshbach resonances

Nature Physics volume 13, pages 731735 (2017) | Download Citation

This article has been updated

Abstract

Efimov physics is a universal phenomenon 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 symmetry1. These Efimov states, first observed in cold caesium atoms2, have been recently reported in a variety of other atomic systems3,4,5,6,7,8,9,10,11,12,13. The intriguing prospect of a universal absolute Efimov resonance position across Feshbach resonances remains an open question. Theories predict a strong dependence on the resonance strength for closed-channel-dominated Feshbach resonances, whereas experimental results have so far been consistent with the universal prediction. Here we directly compare the Efimov spectra in a 6Li–133Cs 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 absolute Efimov resonance position on Feshbach resonance strength and a clear departure from the universal prediction for the narrow Feshbach resonance.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Change history

  • 23 May 2017

    In the version of this Letter originally published, the y axis labels of Fig. 1 were missing the percentage signs. This has now been corrected in all versions of the Letter.

References

  1. 1.

    Energy levels arising from resonant two-body forces in a three-body system. Phys. Lett. B 33, 563–564 (1970).

  2. 2.

    et al. Evidence for Efimov quantum states in an ultracold gas of caesium atoms. Nature 440, 315–318 (2006).

  3. 3.

    , & Universality in three- and four-body bound states of ultracold atoms. Science 326, 1683–1685 (2009).

  4. 4.

    et al. Observation of an Efimov spectrum in an atomic system. Nat. Phys. 5, 586–591 (2009).

  5. 5.

    , , & Observation of universality in ultracold 7Li three-body recombination. Phys. Rev. Lett. 103, 163202 (2009).

  6. 6.

    et al. Universal trimer in a three-component Fermi gas. Phys. Rev. A 80, 040702 (2009).

  7. 7.

    et al. Evidence for an excited-state Efimov trimer in a three-component Fermi gas. Phys. Rev. Lett. 103, 130404 (2009).

  8. 8.

    , , , & Measurements of Tan’s contact in an atomic Bose–Einstein condensate. Phys. Rev. Lett. 108, 145305 (2012).

  9. 9.

    et al. Test of the universality of the three-body Efimov parameter at narrow Feshbach resonances. Phys. Rev. Lett. 111, 053202 (2013).

  10. 10.

    , , & Observation of the second triatomic resonance in Efimov’s scenario. Phys. Rev. Lett. 112, 190401 (2014).

  11. 11.

    , , & Efimov resonance and three-body parameter in a lithium–rubidium mixture. Phys. Rev. Lett. 115, 043201 (2015).

  12. 12.

    , , , & Geometric scaling of Efimov states in a 6Li–133Cs mixture. Phys. Rev. Lett. 113, 240402 (2014).

  13. 13.

    et al. Observation of Efimov resonances in a mixture with extreme mass imbalance. Phys. Rev. Lett. 112, 250404 (2014).

  14. 14.

    et al. Universality of the three-body parameter for Efimov states in ultracold cesium. Phys. Rev. Lett. 107, 120401 (2011).

  15. 15.

    , , & Feshbach resonances in ultracold gases. Rev. Mod. Phys. 82, 1225 (2010).

  16. 16.

    Universal scaling of Efimov resonance positions in cold atom systems. Preprint at (2011).

  17. 17.

    , , & Origin of the three-body parameter universality in Efimov physics. Phys. Rev. Lett. 108, 263001 (2012).

  18. 18.

    , & Efimov physics beyond universality. Eur. Phys. J. B 85, 386–391 (2012).

  19. 19.

    , & Microscopic origin and universality classes of the Efimov three-body parameter. Phys. Rev. Lett. 112, 105301 (2014).

  20. 20.

    , & Physical origin of the universal three-body parameter in atomic Efimov physics. Phys. Rev. A 90, 022106 (2014).

  21. 21.

    & Ultracold three-body collisions near overlapping Feshbach resonances. Phys. Rev. Lett. 103, 083202 (2009).

  22. 22.

    , , & Universal three-body parameter in heteronuclear atomic systems. Phys. Rev. Lett. 109, 243201 (2012).

  23. 23.

    Three-boson problem near a narrow Feshbach resonance. Phys. Rev. Lett. 93, 143201 (2004).

  24. 24.

    , & Analytical solution of the bosonic three-body problem. Phys. Rev. Lett. 100, 140404 (2008).

  25. 25.

    , , & Efimov physics and the three-body parameter within a two-channel framework. Phys. Rev. A 86, 052516 (2012).

  26. 26.

    et al. Ultracold mixtures of atomic 6Li and 133Cs with tunable interactions. Phys. Rev. A 87, 010702 (2013).

  27. 27.

    et al. Universality of weakly bound dimers and Efimov trimers close to LiCs Feshbach resonances. New J. Phys. 17, 055009 (2015).

  28. 28.

    et al. Heteronuclear Efimov scenario with positive intraspecies scattering length. Phys. Rev. Lett. 117, 153201 (2016).

  29. 29.

    , & Ultracold few-body systems. Adv. At. Mol. Opt. Phys. 62, 1–115 (2013).

  30. 30.

    & Scattering length scaling laws for ultracold three-body collisions. Phys. Rev. Lett. 94, 213201 (2005).

Download references

Acknowledgements

We thank Y. Wang, C. Greene and R. Grimm for valuable discussions. We thank L. Feng, C. V. Parker and S.-K. Tung for help in the early stages of the experiment. We acknowledge funding support from NSF Materials Research Science and Engineering Centers grant DMR-1420709 and NSF grant PHY-1511696. Additional support for B.J.D. is provided by the Grainger Fellowship.

Author information

Affiliations

  1. The James Franck Institute, Enrico Fermi Institute, and Department of Physics, The University of Chicago, Chicago, Illinois 60637, USA

    • Jacob Johansen
    • , B. J. DeSalvo
    • , Krutik Patel
    •  & Cheng Chin

Authors

  1. Search for Jacob Johansen in:

  2. Search for B. J. DeSalvo in:

  3. Search for Krutik Patel in:

  4. Search for Cheng Chin in:

Contributions

J.J., B.J.D. and K.P. performed the experiments. C.C. supervised the work. All authors were involved in analysis and discussions of the results and contributed to the preparation of the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Cheng Chin.

Supplementary information

PDF files

  1. 1.

    Supplementary information

    Supplementary information

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nphys4130

Further reading

Newsletter Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing