Flat-band-induced superconductivity in synthetic bilayer optical lattices
arXiv:2207.13013 · doi:10.1103/PhysRevB.106.174503
Abstract
Stacking two layers of graphene with a relative twist angle gives rise to moiré patterns, which can strongly modify electronic behavior and may lead to unconventional superconductivity. A synthetic version of twisted bilayers can be engineered with cold atoms in optical lattices. Here, the bilayer structure is mimicked through coupling between atomic sublevels, and the twist is achieved by a spatial modulation of this coupling. In the present paper, we investigate the superconducting behavior of fermionic atoms in such a synthetic twisted bilayer lattice. Attractive interactions between the atoms are treated on the mean-field level, and the superconducting behavior is analyzed via the self-consistently determined pairing gap. A strong enhancement of the pairing gap is found, when a quasi-flat band structure occurs at the Fermi surface, reflecting the prominent role played by the twist on the superconductivity. The tunability of interactions allows for the switching of superconducting correlations from intra (synthetic) layer to inter (synthetic) layer. This includes also the intermediate scenario, in which the competition between inter- and intra-layer coupling completely destroys the superconducting behavior, resulting in re-entrant superconductivity upon tuning of the interactions
arXiv commentWe warmly dedicate this paper to Prof. Roman Micnas - a pioneer of theory of superconductivity with local electron pairing, who passed away on 13th of January, 2022
References in corpus (44)
- Magic-angle graphene superlattices: a new platform for unconventional superconductivity
- Many-Body Physics with Ultracold Gases
- Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
- Feshbach Resonances in Ultracold Gases
- Moire bands in twisted double-layer graphene
- Ultracold atomic gases in optical lattices: mimicking condensed matter physics and beyond
- Graphene bilayer with a twist: electronic structure
- The electronic properties of bilayer graphene
- Magic continuum in twisted bilayer WSe2
- Origin of Magic Angles in Twisted Bilayer Graphene
- Experimental realization of a long-range antiferromagnet in the Hubbard model with ultracold atoms
- Hubbard model physics in transition metal dichalcogenide moiré bands
- Metallic and Insulating Phases of Repulsively Interacting Fermions in a 3D Optical Lattice
- Superfluidity in topologically nontrivial flat bands
- Synthetic gauge fields in synthetic dimensions
- Moiré heterostructures as a condensed matter quantum simulator
- Tunable Moiré Bands and Strong Correlations in Small-Twist-Angle Bilayer Graphene
- Fermi-Hubbard physics with atoms in an optical lattice
- The Hubbard Model
- High-temperature superfluidity of fermionic atoms in optical lattices
- Quantum simulation of a Fermi-Hubbard model using a semiconductor quantum dot array
- Geometric origin of superfluidity in the Lieb lattice flat band
- Superfluidity and Quantum Geometry in Twisted Multilayer Systems
- Quantum simulation of an extra dimension
- Ultracold Fermi Gases with Emergent SU(N) Symmetry
- Flat bands in topological media
- Geometric and conventional contribution to superfluid weight in twisted bilayer graphene
- Synthetic Dimensions for Cold Atoms from Shaking a Harmonic Trap
- Cold atoms in twisted bilayer optical potentials
- Competing magnetic orders in a bilayer Hubbard model with ultracold atoms
- A route to high temperature superconductivity in composite systems
- Physics of cuprates with the two-band Hubbard model - The validity of the one-band Hubbard model
- Simulating twistronics without a twist
- Approach for making visible and stable stripes in a spin-orbit-coupled Bose-Einstein superfluid
- Detection and manipulation of nuclear spin states in fermionic strontium
- Thermodynamics of a deeply degenerate SU()-symmetric Fermi gas
- Spin-twisted Optical Lattices: Tunable Flat Bands and Larkin-Ovchinnikov Superfluids
- Magic-angle semimetals
- Magic-Angle Semimetals with Chiral Symmetry
- Quantum Many-Body Simulations of the 2D Fermi-Hubbard Model in Ultracold Optical Lattices
- Dynamical disentangling and cooling of atoms in bilayer optical lattices
- Quantum anomalous Hall phase in synthetic bilayers via twistless twistronics
- Proximity effects in cold atom artificial graphene
- A Numerical Perspective on Hartree-Fock-Bogoliubov Theory