Atom-Dimer Scattering and Stability of Bose and Fermi Mixtures

Abstract

Motivated by a recent experiment by ENS group on the mixture of Bose and Fermi superfluids (arxiv:1404.2548), we investigate the effective scattering between a bosonic atom and a molecule(dimer) of fermion atoms. It is found that the mean-field prediction of the atom-dimer scattering length ($a_{ad}$), as simply given by the boson-fermion scattering length ($a_{bf}$), generically fails. Instead, $a_{ad}$ crucially depends on the ratio between $a_{bf}$ and $a_{ff}$ (the fermion-fermion scattering length), and in addition log-periodically depends on the three-body parameter. We identify the universal parameters in characterizing $a_{ad}$ for a wide range of $a_{ff}$ in the molecular side of the fermion-fermion Feshbach resonance, and further demonstrate that the atom-dimer many-body system can become unstable against either phase separation or collapse as tuning $a_{ff}$. Our results have some implications to the ENS experiment.

5+2 pages, 5 figures; accepted version by PRA(R)

References in corpus (9)

• Weakly bound dimers of fermionic atoms
• Observation of an Efimov spectrum in an atomic system
• Collisional stability of a three-component degenerate Fermi gas
• Observation of universality in ultracold 7Li three-body recombination
• Observation of an Efimov-like resonance in ultracold atom-dimer scattering
• Observation of heteronuclear atomic Efimov resonances
• Observation of Efimov Resonances in a Mixture with Extreme Mass Imbalance
• Radio Frequency Association of Efimov Trimers
• Atom-Dimer Scattering in a Three-Component Fermi Gas

Cited by in corpus (9)

• Two-Element Mixture of Bose and Fermi Superfluids
• Polarons in Ultracold Fermi Superfluids
• Calibration of Interaction Energy between Bose and Fermi Superfluids
• Quasi-particle Lifetime in a Mixture of Bose and Fermi Superfluids
• Quantum droplet in a mixture of Bose-Fermi superfluids
• Vortex Lattices in the Bose-Fermi Superfluid Mixture
• Two-dimensional polaron spectroscopy of Fermi superfluids
• Second root of dilute Bose-Fermi mixtures
• Elementary excitations in the hybrid Bose-Fermi system induced by circularly polarized light in a two-dimensional gas of charge carriers with different masses