Chiral flat band superconductivity from symmetry-protected three-band crossings

Abstract

We show that chiral (nearly) flat band superconductivity can develop and host novel Majorana fermions at a time-reversal pair of symmetry-protected three-band crossing points. Based on symmetry analysis, mean-field study, and superfluid stiffness calculation, we determine and analyze the irreducible pairing channels with flat band pairings in the low-energy spin-$1$ fermion theory. Flat band pairing can enhance superconductivity dramatically, where the critical temperature scales linearly in the interaction strength. While fully gapped flat band pairing states develop in the single-component pairing channels, we find chiral $\bar{p}\pm i\bar{p}$ flat band superconductivity in the multicomponent pairing channels. Three-dimensional itinerant Majorana fermions arise at the bulk nodal points, whereas Majorana arcs appear on the surface.

arXiv comment10 pages, 3 figures. v3: Published version

References in corpus (44)

• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Berry Phase Effects on Electronic Properties
• Weyl and Dirac Semimetals in Three Dimensional Solids
• Paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries, and the fractional quantum Hall effect
• Topological superconductors: a review
• Beyond Dirac and Weyl fermions: Unconventional quasiparticles in conventional crystals
• Colloquium: Majorana Fermions in nuclear, particle and solid-state physics
• Chiral superconductivity from repulsive interactions in doped graphene
• Signatures of Gate-Tunable Superconductivity in Trilayer Graphene/Boron Nitride Moiré Superlattice
• Superfluidity in topologically nontrivial flat bands
• High-temperature surface superconductivity in topological flat-band systems
• The Physics of Pair Density Waves
• Chiral Superconductors
• Geometric origin of superfluidity in the Lieb lattice flat band
• Flat bands in topological media
• Band geometry, Berry curvature and superfluid weight
• Topology-Bounded Superfluid Weight In Twisted Bilayer Graphene
• Weyl superconductors
• Bogoliubov Fermi surfaces in superconductors with broken time-reversal symmetry
• Superconductivity of doped Weyl semimetals: finite-momentum pairing and electronic analogues of the 3He-A phase
• Chiral $d$-wave Superconductivity in SrPtAs
• Pairing of j=3/2 fermions in half-Heusler superconductors
• Eliashberg Theory: a short review
• Bogoliubov Fermi surfaces: General theory, magnetic order, and topology
• Topological Maxwell Metal Bands in a Superconducting Qutrit
• Topological nodal Cooper pairing in doped Weyl metals
• Superconductivity in three-dimensional spin-orbit coupled semimetals
• Odd-parity superconductors with two-component order parameters: nematic and chiral, full gap and Majorana node
• Upper bounds on the superfluid stiffness and superconducting $T_c$: Applications to twisted-bilayer graphene and ultra-cold Fermi gases
• Topological superconductivity of spin-3/2 carriers in a three-dimensional doped Luttinger semimetal
• Pairing states of spin-3/2 fermions: Symmetry-enforced topological gap functions
• A chiral twist on the high-$T_c$ phase diagram in Moiré heterostructures
• Topologically protected surface Majorana arcs and bulk Weyl fermions in ferromagnetic superconductors
• Unconventional Superconductivity in Luttinger Semimetals: Theory of Complex Tensor Order and the Emergence of the Uniaxial Nematic State
• Superconducting States in pseudo-Landau Levels of Strained Graphene
• Emergent pseudospin-1 Maxwell fermions with a threefold degeneracy in optical lattices
• Topological Triply Degenerate Points Induced by Spin-Tensor-Momentum Couplings
• Triple point fermions in a minimal symmorphic model
• Three-Dimensional Majorana Fermions in Chiral Superconductors
• Weyl and Dirac Loop Superconductors
• Impurity-induced triple point fermions in twisted bilayer graphene
• The Dirac Composite Fermion of the Fractional Quantum Hall Effect
• Topological density-wave states in a particle-hole symmetric Weyl metal
• Exotic Superconductivity with Enhanced Energy Scales in Three Band Crossing Materials

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