Temperature and doping induced instabilities of the repulsive Hubbard model on Lieb lattice

Abstract

The properties of a phase at finite interactions can be significantly influenced by the underlying dispersion of the non-interacting Hamiltonian. We demonstrate this by studying the repulsive Hubbard model on the $2$D Lieb lattice, which has a flat band for vanishing interaction $U$. We perform real-space dynamical mean-field theory calculations at different temperatures and dopings using a continuous time quantum Monte Carlo impurity solver. Studying the frequency dependence of the self-energy, we show that a finite temperature non-magnetic non-Fermi liquid behavior is a concomitant of the flat band singularity. At half-filling we also find a magnetically ordered region, where the order parameter varies linearly with the interaction strength, and a strongly correlated Mott insulating phase. The double occupancy decreases sharply for small $U$, highlighting the flat band contribution. Away from half-filling, we observe the stripe order, i.e. an inhomogeneous spin and charge density wave of finite wavelength which turns into a sub-lattice ordering at higher temperatures.

10 pages, 11 figures

References in corpus (25)

• Many-Body Physics with Ultracold Gases
• Continuous-time Monte Carlo methods for quantum impurity models
• Nearly-flat bands with nontrivial topology
• Observation of a localized flat-band state in a photonic Lieb lattice
• Observation of bound states in Lieb photonic lattices
• Band geometry, Berry curvature and superfluid weight
• Topological Phases for Fermionic Cold Atoms on the Lieb Lattice
• Disorder-Driven Non-Fermi Liquid Behavior of Correlated Electrons
• Antiferromagnetic Order of Strongly Interacting Fermions in a Trap: Real-Space Dynamical Mean-Field Analysis
• Dual fermion approach to the two-dimensional Hubbard model: Antiferromagnetic fluctuations and Fermi arcs
• Effective theory and emergent $SU(2)$ symmetry in the flat bands of attractive Hubbard models
• Diagrammatic Determinantal methods: projective schemes and applications to the Hubbard-Holstein model
• Local magnetic moments in iron and nickel at ambient and Earth's core conditions
• Local Order and the gapped phase of the Hubbard model: a plaquette dynamical mean field investigation
• Quantum Simulation of the Hubbard Model: The Attractive Route
• Phase diagram of the Kane-Mele-Coulomb model
• Spin Density Waves in the Hubbard model - A DMFT approach
• Cold Attractive Spin Polarized Fermi Lattice Gases and the Doped Positive U Hubbard Model
• Ferromagnetism beyond Lieb's theorem
• Non-Fermi liquid signatures in the Hubbard Model due to van Hove singularities
• Robust flat bands in RCo5 (R=rare earth) compounds
• Canted Antiferromagnetic Order of Imbalanced Fermi-Fermi mixtures in Optical Lattices by Dynamical Mean-Field Theory
• Occurrence of flat bands in strongly correlated Fermi systems and high-$T_c$ superconductivity of electron-doped compounds
• Stripes and electronic quasiparticles in the pseudogap state of cuprate superconductors
• Melting of stripe phases and its signature in the single-particle spectral function