Correlated Phases of Population Imbalanced Fermi-Fermi Mixtures on an Optical Lattice

Abstract

We study a two species fermion mixture with different populations on a square lattice modeled by a Hubbard Hamiltonian with on-site inter-species repulsive interaction. Such a model can be realized in a cold atom system with fermionic atoms in two different hyperfine states loaded on an optical lattice and with tunable inter-species interaction strength via external fields. For a two-dimensional square lattice, when at least one of the fermion species is close to half-filling, the system is highly affected by lattice effects. With the majority species near half-filling and varying densities for the minority species, we find that several correlated phases emerge as the ground state, including a spin density wave state, a charge density wave state with stripe structure, and various p-wave BCS pairing states for both species. We study this system using a functional renormalization group method, determine its phase diagram at weak coupling, discuss the origin and characteristics of each phase, and provide estimates for the critical temperatures.

5 pages, 4 figures, figures updated

References in corpus (18)

• Using photoemission spectroscopy to probe a strongly interacting Fermi gas
• Observation of Phase Separation in a Strongly-Interacting Imbalanced Fermi Gas
• Evidence for Superfluidity of Ultracold Fermions in an Optical Lattice
• Direct Observation of the Superfluid Phase Transition in Ultracold Fermi Gases
• Phase diagram of a two-component Fermi gas with resonant interactions
• Molecules of Fermionic Atoms in an Optical Lattice
• Deformation of a Trapped Fermi Gas with Unequal Spin Populations
• Measuring the one-particle excitations of ultracold fermionic atoms by stimulated Raman spectroscopy
• Induced P-wave Superfluidity in Asymmetric Fermi Gases
• Engineering Superfluidity in Bose-Fermi Mixtures of Ultracold Atoms
• Competing Orders in two-dimensional Bose-Fermi mixtures
• Superfluid and insulating phases of fermion mixtures in optical lattices
• Exotic Superconducting Phases of Ultracold Atom Mixtures on Triangular Lattices
• Pairing and density-wave phases in Boson-Fermion mixtures at fixed filling
• Canted Antiferromagnetic Order of Imbalanced Fermi-Fermi mixtures in Optical Lattices by Dynamical Mean-Field Theory
• Quantum phases of Fermi-Fermi mixtures in optical lattices
• Induced p-wave superfluidity in strongly interacting imbalanced Fermi gases
• Antiferromagnetic Order of Repulsively Interacting Fermions on Optical lattices

Cited by in corpus (2)

• Interorbital Interactions in an SU(2)xSU(6)-Symmetric Fermi-Fermi Mixture
• Possible quantum phase-manipulation of a two-leg ladder in mixed-dimensional fermionic cold atoms