Attractive Hubbard Model on a Honeycomb Lattice

Abstract

We study the attractive fermionic Hubbard model on a honeycomb lattice using determinantal quantum Monte Carlo simulations. By increasing the interaction strength U (relative to the hopping parameter t) at half-filling and zero temperature, the system undergoes a quantum phase transition at 5.0 < U_c/t < 5.1 from a semi-metal to a phase displaying simultaneously superfluid behavior and density order. Doping away from half-filling, and increasing the interaction strength at finite but low temperature T, the system always appears to be a superfluid exhibiting a crossover between a BCS and a molecular regime. These different regimes are analyzed by studying the spectral function. The formation of pairs and the emergence of phase coherence throughout the sample are studied as U is increased and T is lowered.

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Cited by in corpus (18)

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• Quantum Multicriticality near the Dirac-Semimetal to Band-Insulator Critical Point in Two Dimensions: A Controlled Ascent from One Dimension
• Unruh effect for interacting particles with ultracold atoms
• Quantum phase transitions in Dirac fermion systems
• Supersolid Phase Accompanied by a Quantum Critical Point in the Intermediate Coupling Regime of the Holstein Model
• Proximity effects in cold atom artificial graphene
• Calculating ground state properties of correlated fermionic systems with BCS trial wave functions in Slater determinant path-integral approaches
• Semimetal-superfluid quantum phase transitions in 2D and 3D lattices with Dirac points
• Trion states and quantum criticality of attractive SU(3) Dirac fermions
• Superfluid stiffness for the attractive Hubbard model on a honeycomb optical lattice
• Reentrant Fulde-Ferrell-Larkin-Ovchinnikov superfluidity in the honeycomb lattice
• Anomalous Spin Dynamics of Hubbard Model on Honeycomb Lattices
• Charge excitations across a superconductor-insulator transition
• Superconductivity and pair density waves from nearest-neighbor interactions in frustrated lattice geometries
• Sudden-quench dynamics of Bardeen-Cooper-Schrieffer states in deep optical lattices
• Spin-polarized superconducting phase in semiconducting system with next-nearest-neighbor hopping on the honeycomb lattice
• Coexisting Néel and charge density wave orders in attractive three-color fermions
• Trion formation and ordering in the attractive SU(3) Fermi-Hubbard model