Confinement versus deconfinement of Cooper Pairs in One-Dimensional Spin-3/2 Fermionic Cold Atoms

Sylvain Capponi (1, 2) , Guillaume Roux (1, 2) , P. Azaria (3) , E. Boulat (4) , P. Lecheminant (5)

1 FFC - Fermions Fortement Corrélés (LPT)
2 LPT - Laboratoire de Physique Théorique
3 LPTMC - Laboratoire de Physique Théorique de la Matière Condensée
4 MPQ (UMR_7162) - Laboratoire Matériaux et Phénomènes Quantiques
5 LPTM - UMR 8089 - Laboratoire de Physique Théorique et Modélisation

The phase diagram of spin-3/2 fermionic cold atoms trapped in a one-dimensional optical lattice is investigated at quarter filling (one atom per site) by means of large-scale numerical simulations. In full agreement with a recent low-energy approach, we find two phases with confined and deconfined Cooper pairs separated by an Ising quantum phase transition. The leading instability in the confined phase is an atomic-density wave with subdominant quartet superfluid instability made of four fermions. At sufficiently low densities, we find that the quartet instability dominates and marks the onset of a nematic Luttinger liquid phase associated to the pairing of Cooper pairs.

Domaines: Supraconductivité [cond-mat.supr-con]

Sylvain Capponi, Guillaume Roux, P. Azaria, E. Boulat, P. Lecheminant. Confinement versus deconfinement of Cooper Pairs in One-Dimensional Spin-3/2 Fermionic Cold Atoms. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2007, 75 (10), pp.100503(R). ⟨10.1103/PhysRevB.75.100503⟩. ⟨hal-00121404⟩