Stability of fermionic Feshbach molecules in a Bose-Fermi mixture (6 pages)

Daniele C. E. Bortolotti, А. V. Avdeenkov, John L. Bohn

Michele Lynn Olsen

Ming-Guang Hu, Tyler D. Cumby, Ruth Shewmon +1 more

徹 鈴木

А. V. Avdeenkov, Daniele C. E. Bortolotti, John L. Bohn

In the wake of successful experiments in Fermi condensates, experimental attention is broadening to study resonant interactions in degenerate Bose-Fermi mixtures. Here, we consider the properties and stability of the fermionic molecules that can be created in such a mixture near a Feshbach resonance. To do this, we consider the two-body scattering matrix in the many-body environment, and assess its complex poles. The stability properties of these molecules strongly depend on their center-of-mass motion, because they must satisfy Fermi statistics. At low center-of-mass momenta the molecules are more stable than in the absence of the environment (due to Pauli-blocking effects), while at high center-of-mass momenta nontrivial many-body effects render them somewhat less stable.

J. J. Zirbel, Kang-Kuen Ni, Silke Ospelkaus +4 more

Using a Feshbach resonance, we create ultracold fermionic molecules starting from a Bose-Fermi atom gas mixture. The resulting mixture of atoms and weakly bound molecules provides a rich system for studying few-body collisions because of the variety of atomic collision partners for molecules; either bosonic, fermionic, or distinguishable atoms. Inelastic loss of the molecules near the Feshbach resonance is dramatically affected by the quantum statistics of the colliding particles and the scattering length. In particular, we observe a molecule lifetime as long as 100 ms near the Feshbach resonance.