Topological chiral superconductivity beyond pairing in a Fermi liquid

Abstract

We investigate a mechanism to produce superconductivity by strong purely repulsive interactions for flat dispersion $\epsilon \sim k^4$, without using pairing instability in Fermi-liquid. The resulting superconductors break both time-reversal and reflection symmetries in the orbital motion of electrons, and exhibit non-trivial topological order. Our findings suggest that this topological chiral superconductivity is more likely to emerge near or between fully spin-valley polarized metallic phase and Wigner crystal phase. These topological chiral superconductors can be fully or partially spin-valley polarized. For partial spin-valley polarization, the ratios of electron densities associated with different spin-valley quantum numbers are quantized as simple rational numbers. Furthermore, many of these topological chiral superconductors exhibit charge-4 or higher condensation, neutral quasiparticles with fractional statistics, and/or gapless chiral edge states. Two of the topological chiral superconductors are in the same phases as the ``spin''-triplet or spinless $p+\text{i}p$ BCS superconductor, while others are in different phases than any BCS superconductors. The same mechanism is also used to produce anyon superconductivity between fractional anomalous quantum Hall states in the presence of a periodic potential.

23 pages, 4 figures, 3 tables

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Cited by in corpus (14)

• Anyon Superconductivity from Topological Criticality in a Hofstadter-Hubbard Model
• Doping a fractional quantum anomalous Hall insulator
• Microscopic Mechanism of Anyon Superconductivity Emerging from Fractional Chern Insulators
• Quarter Metal Superconductivity
• Probing superconductivity with tunneling spectroscopy in rhombohedral graphene
• Momentum-resolved spectroscopy of superconductivity with the quantum twisting microscope
• Pathways from a chiral superconductor to a composite Fermi liquid
• Finite-momentum pairing and superlattice superconductivity in valley-imbalanced rhombohedral graphene
• In-plane magnetic field-induced orbital FFLO superconductivity in twisted WSe${}_2$ homobilayers
• Variational Monte Carlo Optimization of Topological Chiral Superconductors
• Sensing the binding and unbinding of anyons at impurities
• Family of multilayer graphene superconductors with tunable chirality: Momentum-space vortices nucleated by a ring of Berry curvature
• Emblems of pair density waves: dual identity of topological defects and their transport signatures
• Repulsive-Interaction-Driven Topological Superconductivity in a Landau Level Coupled to an $s$-Wave Superconductor