English

Broad Feshbach resonance with a large background scattering length in a fermionic atom-molecule mixture

Quantum Gases 2025-11-25 v1 Atomic Physics

Abstract

We report the observation of a broad magnetic Feshbach resonance with a large background scattering length in an ultracold fermionic mixture of 23^{23}Na40^{40}K molecules and 40^{40}K atoms, with both species prepared in their lowest hyperfine states. The Feshbach resonance is characterized by measuring resonantly enhanced loss rates and elastic scattering cross sections via cross-species thermalization. The large background scattering length can drive the atom-molecule mixture into the hydrodynamic regime when the magnetic field is far from the resonance. We observe that the center-of-mass motions of the atoms and molecules are phase-locked and oscillate with a common frequency due to hydrodynamic drag effects. This broad atom-molecule Feshbach resonance with its large background scattering length opens up a new avenue towards studying strongly interacting fermionic gases with mass imbalance.

Keywords

Cite

@article{arxiv.2511.06772,
  title  = {Broad Feshbach resonance with a large background scattering length in a fermionic atom-molecule mixture},
  author = {Zhen Su and Tong-Hui Shou and Huan Yang and Jin Cao and Bo-Yuan Wang and Ting Xie and Jun Rui and Bo Zhao and Jian-Wei Pan},
  journal= {arXiv preprint arXiv:2511.06772},
  year   = {2025}
}

Comments

8 pages, 6 figures

R2 v1 2026-07-01T07:29:03.148Z