Spin-fluctuation-induced pairing in twisted bilayer graphene

Abstract

We investigate the interplay of magnetic fluctuations and Cooper pairing in twisted bilayer graphene from a purely microscopic model within a large-scale tight-binding approach resolving the Ångström scale. For local onsite repulsive interactions and using the random-phase approximation for spin fluctuations, we derive a microscopic effective pairing interaction that we use for self-consistent solutions of the Bogoliubov-de-Gennes equations of superconductivity. We study the predominant pairing types as function of interaction strength, temperature and band filling. For large regions of this parameter space, we find chiral $d$-wave pairing regimes, spontaneously breaking time-reversal symmetry, separated by magnetic instabilities at integer band fillings. Interestingly, the $d$-wave pairing is strongly concentrated in the AA regions of the moiré unit cell and exhibits phase windings of integer multiples of $2\pi$ around these superconducting islands, i.e. pinned vortices. The spontaneous circulating current creates a distinctive magnetic field pattern. This signature of the chiral pairing should be measurable by state-of-the-art experimental techniques.

arXiv comment5 pages, 3 figures

References in corpus (47)

• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
• Tuning superconductivity in twisted bilayer graphene
• Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene
• Superconductors, Orbital Magnets, and Correlated States in Magic Angle Bilayer Graphene
• Intrinsic quantized anomalous Hall effect in a moiré heterostructure
• Observation of Van Hove singularities in twisted graphene layers
• Optical detection of Mott and generalized Wigner crystal states in WSe2/WS2 moiré superlattices
• Magic continuum in twisted bilayer WSe2
• Magic Angle Spectroscopy
• Imaging Electronic Correlations in Twisted Bilayer Graphene near the Magic Angle
• Electric Field Tunable Correlated States and Magnetic Phase Transitions in Twisted Bilayer-Bilayer Graphene
• Charge-Order and Broken Rotational Symmetry in Magic Angle Twisted Bilayer Graphene
• Signatures of Gate-Tunable Superconductivity in Trilayer Graphene/Boron Nitride Moiré Superlattice
• Spectroscopic signatures of many-body correlations in magic angle twisted bilayer graphene
• Continuum Model of the Twisted Bilayer
• Spin-polarized Correlated Insulator and Superconductor in Twisted Double Bilayer Graphene
• Correlated states in twisted double bilayer graphene
• Maximally-localized Wannier orbitals and the extended Hubbard model for the twisted bilayer graphene
• Strength of effective Coulomb interactions in graphene and graphite
• Untying the insulating and superconducting orders in magic-angle graphene
• Optical Absorption in Twisted Bilayer Graphene
• Topological Superconductivity in Twisted Multilayer Graphene
• Chiral SDW and d + id superconductivity in the magic-angle twisted bilayer-graphene
• Correlated Insulating States in Twisted Double Bilayer Graphene
• Density waves and Cooper pairing on the honeycomb lattice
• Optimal Hubbard models for materials with nonlocal Coulomb interactions: graphene, silicene and benzene
• Topologically Protected Helical States in Minimally Twisted Bilayer Graphene
• Strong Correlations and d+id Superconductivity in Twisted Bilayer Graphene
• Tunable correlation-driven symmetry breaking in twisted double bilayer graphene
• Chiral d-wave superconductivity in doped graphene
• Multi-flat bands and strong correlations in Twisted Bilayer Boron Nitride
• Electrically controllable magnetism in twisted bilayer graphene
• Electronic spectrum of twisted bilayer graphene
• Quantum limits to the energy resolution of magnetic field sensors
• One-dimensional flat bands in twisted bilayer germanium selenide
• Electrically Tunable Flat Bands and Magnetism in Twisted Bilayer Graphene
• Wannier Function Approach to Realistic Coulomb Interactions in Layered Materials and Heterostructures
• Pairing symmetry and spontaneous vortex-antivortex lattice in superconducting twisted-bilayer graphene: Bogoliubov-de Gennes approach
• Interaction driven metal-insulator transition in strained graphene
• Pairing in graphene-based moiré superlattices
• Microscopic pairing mechanism, order parameter, and disorder sensitivity in moiré superlattices: Applications to twisted double-bilayer graphene
• Competing pairing channels in the doped honeycomb lattice Hubbard model
• Inherited and flatband-induced ordering in twisted graphene bilayers
• Functional renormalization group for a large moiré unit cell
• Antiferromagnetism and competing charge instabilities of electrons in strained graphene from Coulomb interactions
• Local modulations of the spin-fluctuation mediated pairing interaction by impurities in d-wave superconductors

Cited by in corpus (31)

• Superconductivity in twisted bilayer WSe${}_2$
• Correlated insulators, semimetals, and superconductivity in twisted trilayer graphene
• Unconventional Superconductivity in Magic-Angle Twisted Trilayer Graphene
• Light-matter coupling and quantum geometry in moiré materials
• Charge-$4e$ superconductivity from nematic superconductors in 2D and 3D
• Nematic superconductivity in magic-angle twisted bilayer graphene from atomistic modeling
• Importance of long-ranged electron-electron interactions for the magnetic phase diagram of twisted bilayer graphene
• Nodal band-off-diagonal superconductivity in twisted graphene superlattices
• Electric-field-tunable electronic nematic order in twisted double-bilayer graphene
• TU${}^2$FRG -- a scalable approach for truncated unity functional renormalization group in generic fermionic models
• Flat bands, electron interactions and magnetic order in magic-angle mono-trilayer graphene
• Optical Manipulation of Domains in Chiral Topological Superconductors
• Moiré Engineering of Spin-Orbit Coupling in Twisted Platinum Diselenide
• Superconductivity and magnetism in the surface states of ABC-stacked multilayer graphene
• Coreless vortices as direct signature of chiral $d$-wave superconductivity
• Theory of intervalley-coherent AFM order and topological superconductivity in tWSe${}_2$
• Spin and Charge Fluctuation Induced Pairing in ABCB Tetralayer Graphene
• Scaling theory of intrinsic Kondo and Hund's rule interactions in magic-angle twisted bilayer graphene
• Robust and tunable coreless vortices and fractional vortices in chiral $d$-wave superconductors
• Doping fingerprints of spin and lattice fluctuations in moiré superlattice systems
• Moir{é} pattern assisted geometric resonant tunneling in disordered twisted bilayer graphene
• Intrinsic non-magnetic ${\varphi }_0$ Josephson junctions in twisted bilayer graphene
• Spin excitations in the heavily overdoped monolayer graphene superconductor: an analog to the cuprates
• Superconductivity from spin fluctuations and long-range interactions in magic-angle twisted bilayer graphene
• Enhanced chiral edge currents and orbital magnetic moment in chiral $d$-wave superconductors from mesoscopic finite-size effects
• Short vs. long range exchange interactions in twisted bilayer graphene
• Negative electronic compressibility in charge islands in twisted bilayer graphene
• Nematicity Arising from a Chiral Superconducting Ground State in Magic-Angle Twisted Bilayer Graphene under In-Plane Magnetic Fields
• Geometric inhibition of superflow in single-layer graphene suggests a staggered-flux superconductivity in bilayer and trilayer graphene
• Magnetic Ordering in Moiré Graphene Multilayers from a Continuum Hartree+U Approach
• Designing edge currents using mesoscopic patterning in chiral d-wave superconductors