Nonuniversal efimov atom-dimer resonances in a three-component mixture of Li6

Takashi Mukaiyama

Shuta Nakajima, Munekazu Horikoshi, Masahito Ueda +1 more

Shuta Nakajima, Munekazu Horikoshi, Takashi Mukaiyama +2 more

We observed an enhanced atom-dimer loss due to the existence of Efimov states in a three-component mixture of 6Li atoms. We measured the magnetic-field dependence of the atom-dimer loss in the mixture of atoms in state |1> and dimers formed in states |2> and |3>, and found two peaks corresponding to the degeneracy points of the energy levels of |23> dimers and the ground and first excited Efimov trimers. We found that the locations of these peaks disagree with universal theory predictions, in a way that cannot be explained by nonuniversal two-body properties. We constructed theoretical models that characterize the nonuniversal three-body physics of three-component 6Li atoms in the low-energy domain.

Shuta Nakajima, Munekazu Horikoshi, Takashi Mukaiyama +2 more

The binding energy of an Efimov trimer state was precisely determined via radio-frequency association. It is found that the measurement results shift significantly with temperature, but that the shift becomes negligible at the lowest temperature in our experiment. The shift-free part of the trimer binding energy reveals a significant deviation from the nonuniversal theory prediction based on a three-body parameter with a monotonic binding-energy dependence.

Daekyoung Kang, Eric Braaten, H.‐W. Hammer +1 more

Eric Braaten, H.‐W. Hammer, Daekyoung Kang +1 more

A new narrow three-atom loss resonance associated with an Efimov trimer crossing the three-atom threshold has recently been discovered in a many-body system of ultracold $^{6}\mathrm{Li}$ atoms in the three lowest hyperfine spin states at a magnetic field near 895 G. O'Hara and coworkers have used measurements of the three-body recombination rate in this region to determine the complex three-body parameter associated with Efimov physics. Using this parameter as the input, we calculate the universal predictions for the spectrum of Efimov states and for the three-body recombination rate in the universal region above 600 G where all three scattering lengths are large. We predict an atom-dimer loss resonance at $672\ifmmode\pm\else\textpm\fi{}2$ G associated with an Efimov trimer disappearing through an atom-dimer threshold. We also predict an interference minimum in the three-body recombination rate at $759\ifmmode\pm\else\textpm\fi{}1$ G where the three-spin mixture may be sufficiently stable to allow experimental study of the many-body system.