Enhanced correlations and superconductivity in weakly interacting partially flat band systems: a determinantal quantum Monte Carlo study
arXiv:1811.08848 · doi:10.1103/PhysRevB.99.235128
Abstract
Motivated by recent experiments realizing correlated phenomena and superconductivity in 2D van der Waals devices, we consider the general problem of whether correlation effects may be enhanced by modifying band structure while keeping a fixed weak interaction strength. Using determinantal quantum Monte Carlo, we study the 2D Hubbard model for two different band structures: a regular nearest-neighbor tight-binding model, and a partially flat band structure containing a non-dispersing region, with identical total non-interacting bandwidth . For both repulsive and attractive weak interactions (), correlated phenomena are significantly stronger in the partially flat model. In the repulsive case, even with an order of magnitude smaller than , we find the presence of a Mott insulating state near half-filling of the flat region in momentum space. In the attractive case, where generically the ground state is superconducting, the partially flat model exhibits significantly enhanced superconducting transition temperatures. These results suggest the possibility of engineering correlation effects in materials by tuning the non-interacting electronic dispersion.
References in corpus (44)
- Two-Dimensional Gas of Massless Dirac Fermions in Graphene
- Experimental Observation of Quantum Hall Effect and Berry's Phase in Graphene
- Magic-angle graphene superlattices: a new platform for unconventional superconductivity
- Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
- Moire bands in twisted double-layer graphene
- Unconventional sign-reversing superconductivity in LaFeAsO_(1-x)F_x
- Energy gaps, topological insulator state and zero-field quantum Hall effect in graphene by strain engineering
- Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsOF}
- A Common Thread: the pairing interaction for the unconventional superconductors
- Quantum Cluster Theories
- Theory of Intertwined Orders in High Temperature Superconductors
- Flat Bands in Slightly Twisted Bilayer Graphene
- Hubbard model physics in transition metal dichalcogenide moiré bands
- Localization of Dirac electrons by Moire patterns in graphene bilayers
- Stripe order in the underdoped region of the two-dimensional Hubbard model
- Origin of Mott insulating behavior and superconductivity in twisted bilayer graphene
- Topological confinement in bilayer graphene
- Theory of phonon-mediated superconductivity in twisted bilayer graphene
- Commensuration and Interlayer Coherence in Twisted Bilayer Graphene
- Competing states in the t-J model: uniform d-wave state versus stripe state
- Solutions of the Two Dimensional Hubbard Model: Benchmarks and Results from a Wide Range of Numerical Algorithms
- Topological Superconductivity in Twisted Multilayer Graphene
- Valley Chern Numbers and Boundary Modes in Gapped Bilayer Graphene
- Model for Metal-Insulator Transition in Graphene Superlattices and Beyond
- Systematic study of d-wave superconductivity in the 2D repulsive Hubbard model
- Phases of a phenomenological model of twisted bilayer graphene
- Electronic Structure Theory of Weakly Interacting Bilayers
- Unconventional superconductivity in nearly flat bands in twisted bilayer graphene
- Mean-field theory for superconductivity in twisted bilayer graphene
- Doped Twisted Bilayer Graphene near Magic Angles: Proximity to Wigner Crystallization not Mott Insulation
- Pairing symmetry of interacting fermions on twisted bilayer graphene superlattice
- Kekulé valence bond order in an extended Hubbard model on the honeycomb lattice, with possible applications to twisted bilayer graphene
- Graphite, graphene and the flat band superconductivity
- Stripe order from the perspective of the Hubbard model
- Topological kink states at a tilt boundary in gated multi-layer graphene
- Charge-transfer insulation in twisted bilayer graphene
- Superconducting Transitions in Flat Band Systems
- Critical temperature for the two-dimensional attractive Hubbard Model
- Geometry Dependence of the Sign Problem
- Topology of the Fermi Surface Beyond the Quantum Critical Point
- Pairing and superconductivity in the flat band: Creutz lattice
- Competition of electron-phonon mediated superconductivity and Stoner magnetism on a flat band
- Lowest-energy Moiré Band Formed by Dirac Zero Modes in Twisted Bilayer Graphene
- New state of matter: heavy-fermion systems, quantum spin liquids, quasicrystals, cold gases, and high temperature superconductors
Cited by in corpus (12)
- Theoretical possibilities for flat-band superconductivity
- Pairing and non-Fermi liquid behavior in partially flat-band systems
- Stable Flatbands, Topology, and Superconductivity of Magic Honeycomb Networks
- An Amelioration for the Sign Problem: Adiabatic Quantum Monte Carlo
- Magnetization, d-wave superconductivity and non-Fermi liquid behavior in a crossover from dispersive to flat bands
- Thermodynamics of correlated electrons in a magnetic field
- Pressure-induced superconductivity in kagome single crystal Pd3P2S8
- Nematicity-enhanced superconductivity in systems with a non-Fermi liquid behavior
- Disorder in interacting quasi-one-dimensional systems: flat and dispersive bands
- Flat bands in condensed-matter systems -- perspective for magnetism and superconductivity
- Insulator-pseudogap crossover in the Lieb lattice
- Stoner ferromagnetism in a momentum-confined interacting 2D electron gas