Loosely Bound Few-Body States in a Spin-1 Gas with Near-Degenerate Continua

Abstract

A distinguishing feature of ultracold collisions of bosonic lithium atoms is the presence of two near-degenerate two-body continua. The influence of such a near-degeneracy on the few-body physics in the vicinity of a narrow Feshbach resonance is investigated within the framework of a minimal model with two atomic continua and one closed molecular channel. The model allows analysis of the spin composition of loosely bound dimers and trimers. In the two-body sector the well-established coupled-channels calculations phenomenology of lithium is qualitatively reproduced, and its particularities are emphasized and clarified. In the three-body sector we find that the Efimov trimer energy levels follow a different functional form as compared to a single continuum scenario while the thresholds remain untouched. This three-channel model with two atomic continua complements our earlier developed three-channel model with two molecular channels [Y. Yudkin and L. Khaykovich, Phys. Rev. A 103, 063303 (2021)] and suggests that the experimentally observed exotic behavior of the first excited Efimov energy level [Y. Yudkin, R. Elbaz and L. Khaykovich, arXiv:2004.02723] is most probably caused by the short-range details of the interaction potential.

15 pages, 11 figures

References in corpus (21)

• Resonantly-paired fermionic superfluids
• Observation of an Efimov spectrum in an atomic system
• Three-body recombination in a three-state Fermi gas with widely tunable interactions
• Three-boson problem near a narrow Feshbach resonance
• Evidence for Universal Four-Body States Tied to an Efimov Trimer
• Two and Three-body Contacts in the Unitary Bose Gas
• Microscopic Origin and Universality Classes of the Efimov Three-Body Parameter
• Universal van der Waals Physics for Three Ultracold Atoms
• Catching Bethe phantoms and quantum many-body scars: Long-lived spin-helix states in Heisenberg magnets
• Study of Efimov physics in two nuclear-spin sublevels of 7Li
• Contrasting the wide Feshbach resonances in ${}^6$Li and ${}^7$Li
• New type of crossover physics in three-component Fermi gases
• Observation of Efimov Universality across a Non-Universal Feshbach Resonance in \textsuperscript{39}K
• Resonant atom-dimer collisions in cesium: Testing universality at positive scattering lengths
• Pinpointing Feshbach Resonances and Testing Efimov Universalities in ${}^{39}$K
• Probing open- and closed-channel p-wave resonances
• Multichannel effects in the Efimov regime from broad to narrow Feshbach resonances
• Strong spin-exchange recombination of three weakly interacting ${}^7$Li atoms
• Efimov scenario for overlapping narrow Feshbach resonances
• Three-body spin mixing in spin-1 Bose-Einstein condensates
• Efimov resonance position near a narrow Feshbach resonance in ${}^6$Li-${}^{133}$Cs mixture

Cited by in corpus (4)

• Reshaped Three-Body Interactions and the Observation of an Efimov State in the Continuum
• Emergent inflation of the Efimov spectrum under three-body spin-exchange interactions
• Resonance-facilitated three-channel p-wave scattering
• Accurate simulation of Efimov physics in ultracold atomic gases with realistic three-body multichannel interactions