Spin 3/2 fermions with attractive interactions in a one-dimensional optical lattice: phase diagrams, entanglement entropy, and the effect of the trap

Abstract

We study spin 3/2 fermionic cold atoms with attractive interactions confined in a one-dimensional optical lattice. Using numerical techniques, we determine the phase diagram for a generic density. For the chosen parameters, one-particle excitations are gapped and the phase diagram is separated into two regions: one where the two-particle excitation gap is zero, and one where it is finite. In the first region, the two-body pairing fluctuations (BCS) compete with the density ones. In the other one, a molecular superfluid (MS) phase, in which bound-states of four particles form, competes with the density fluctuations. The properties of the transition line between these two regions is studied through the behavior of the entanglement entropy. The physical features of the various phases, comprising leading correlations, Friedel oscillations, and excitation spectra, are presented. To make the connection with experiments, the effect of a harmonic trap is taken into account. In particular, we emphasize the conditions under which the appealing MS phase can be realized, and how the phases could be probed by using the density profiles and the associated structure factor. Lastly, the consequences on the flux quantization of the different nature of the pairing in the BCS and MS phases are studied in a situation where the condensate is in a ring geometry.

15 pages, 21 figures

References in corpus (20)

• Many-Body Physics with Ultracold Gases
• The ALPS project release 1.3: open source software for strongly correlated systems
• Bosonizing one-dimensional cold atomic gases
• Collisional stability of a three-component degenerate Fermi gas
• Ultracold fermions and the SU(N) Hubbard model
• Generalized Directed Loop Method for Quantum Monte Carlo Simulations
• Competing orders in one dimensional spin 3/2 fermionic systems
• Pairing states of a polarized Fermi gas trapped in a one-dimensional optical lattice
• Local quantum criticality in confined fermions on optical lattices
• Holonomic quantum computation in decoherence-free subspaces
• Spatial correlations of trapped 1d bosons in an optical lattice
• BCS pairing in Fermi systems with several flavors
• Trionic phase of ultracold fermions in an optical lattice: A variational study
• Tomonaga-Luttinger parameters for doped Mott insulators
• Confinement vs Deconfinement of Cooper Pairs in One-Dimensional Spin-3/2 Fermionic Cold Atoms
• Luther-Emery Phase and Atomic-Density Waves in a Trapped Fermion Gas
• Magnetic Phase Transitions in One-dimensional Strongly Attractive Three-Component Ultracold Fermions
• Spectral convexity for attractive SU(2N) fermions
• Stability of Inhomogeneous Multi-Component Fermi Gases
• Magnetic Stability Analysis for Abelian and Non-Abelian Superconductors

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