Crystalline phase of strongly interacting Fermi mixtures

D. S. Petrov 1, 2, G. E. Astrakharchik 3, D. J. Papoular 1, C. Salomon 4, G. V. Shlyapnikov 1, 5

Physical Review Letters 99 (2007) 130407

We show that the system of weakly bound molecules of heavy and light fermionic atoms is characterized by a long-range intermolecular repulsion and can undergo a gas-crystal quantum transition if the mass ratio exceeds a critical value. For the critical mass ratio above 100 obtained in our calculations, this crystalline order can be observed as a superlattice in an optical lattice for heavy atoms with a small filling factor. We also find that this novel system is sufficiently stable with respect to molecular relaxation into deep bound states and to the process of trimer formation.

  • 1. Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS),
    CNRS : UMR8626 – Université Paris XI - Paris Sud
  • 2. National Research Centre "Kurchatov Institute" (NRC KI),
    University of Moscow
  • 3. Departament de Fisica i Enginyeria Nuclear, Campus Nord B4-B5,
    Universitat Politécnica de Catalunya
  • 4. Laboratoire Kastler Brossel (LKB (Lhomond)),
    CNRS : UMR8552 – Université Paris VI - Pierre et Marie Curie – Ecole Normale Supérieure de Paris - ENS Paris
  • 5. Van der Waals-Zeeman Institute,
    University of Amsterdam