Chern Fermi pocket, topological pair density wave, and charge-4e and charge-6e superconductivity in kagome superconductors

Abstract

The recent discovery of novel charge density wave (CDW) and pair density wave (PDW) in kagomé lattice superconductors $A$V${}_3$Sb${}_5$ ($A=$ K, Rb, Cs) hints at unexpected time-reversal symmetry breaking correlated and topological states whose physical origin and broader implications are not understood. Here, we make conceptual advances toward a mechanism behind the striking observations and new predictions for novel macroscopic phase coherent quantum states. We show that the metallic CDW state with circulating loop currents is a doped orbital Chern insulator near van Hove filling. The emergent Chern Fermi pockets (CFPs) carry concentrated Berry curvature and orbital magnetic moment. We find that the pairing of electrons on the CFPs leads to a superconducting state with an emergent vortex-antivortex lattice and the formation of a complex triple-\textbf{Q} PDW. A plethora of correlated and topological states emerge, including a never-before-encountered chiral topological PDW superconductor, a loop-current pseudogap phase, and vestigial charge-4$e$ and charge-6$e$ superconductivity in staged melting of the vortex-antivortex lattice and hexatic liquid crystal. Our findings reveal previously unknown nature of the superconducting state of a current-carrying Chern metal, with broad implications for correlated and topological materials.

11 pages, 8 figures,

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• Unconventional Fermi surface instabilities in the Kagome Hubbard Model
• Negative flat band magnetism in a spin-orbit coupled correlated kagome magnet
• Charge $4e$ superconductivity from pair density wave order in certain high temperature superconductors
• Electronic Nature of Charge Density Wave and Electron-Phonon Coupling in Kagome Superconductor KV${}_3$Sb${}_5$
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• Doped Kagome System as Exotic Superconductor
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• Revealing the immediate formation of two-fold rotation symmetry in charge-density-wave state of Kagome superconductor CsV${}_3$Sb${}_5$ by optical polarization rotation measurement
• Unidirectional coherent quasiparticles in the high-temperature rotational symmetry broken phase of AV3Sb5 kagome superconductors
• Distinctive momentum dependent charge-density-wave gap observed in CsV${}_3$Sb${}_5$ superconductor with topological Kagome lattice
• Loop-current charge density wave driven by long-range Coulomb repulsion on the kagome lattice
• Electrically controlled superconductor-insulator transition and giant anomalous Hall effect in kagome metal CsV3Sb5 nanoflakes
• Multidome superconductivity in charge density wave kagome metals

Cited by in corpus (77)

• AV${}_3$Sb${}_5$ Kagome Superconductors: Progress and Future Directions
• Superconducting diode effect and interference patterns in Kagome CsV3Sb5
• Chiral kagome superconductivity modulations with residual Fermi arcs in KV3Sb5 and CsV3Sb5
• Unidirectional coherent quasiparticles in the high-temperature rotational symmetry broken phase of AV3Sb5 kagome superconductors
• Charge-loop current order and Z3 nematicity mediated by bond-order fluctuations in kagome metal AV3Sb5 (A=Cs,Rb,K)
• Loop-current charge density wave driven by long-range Coulomb repulsion on the kagome lattice
• Theory of nematic charge orders in kagome metals
• Charge-4e and charge-6e flux quantization and higher charge superconductivity in kagome superconductor ring devices
• Enhanced Spin-polarization via Partial Ge1-dimerization as the Driving Force of the 2$\times$2$\times$2 CDW in FeGe
• Intertwined van-Hove Singularities as a Mechanism for Loop Current Order in Kagome Metals
• Small Fermi pockets intertwined with charge stripes and pair density wave order in a kagome superconductor
• Charge 4e superconductivity and chiral metal in the $45^{\circ }$-twisted bilayer cuprates and similar bilayers
• Monolayer Kagome Metals AV${}_3$Sb${}_5$
• Emergent flat band and topological Kondo semimetal driven by orbital-selective correlations
• Drastic magnetic-field-induced chiral current order and emergent current-bond-field interplay in kagome metals
• Sublattice modulated superconductivity in the Kagome Hubbard model
• Absence of $E_{2g}$ nematic instability and dominant $A_{1g}$ response in the kagome metal CsV${}_3$Sb${}_5$
• Origin of $\pi$-shifted three-dimensional charge density waves in kagome metal AV${}_3$Sb${}_5$
• Tensor network approach to the fully frustrated XY model on a kagome lattice with a fractional vortex-antivortex pairing transition
• Emergent topological quantum orbits in the charge density wave phase of kagome metal CsV${}_3$Sb${}_5$
• Probing orbital magnetism of a kagome metal CsV3Sb5 by a tuning fork resonator
• Kagome metals
• Nematic Superconductivity and Its Critical Vestigial Phases in the Quasi-crystal
• Evidence of a distinct collective mode in Kagome superconductors
• Chiral-Flux-Phase-Based Topological Superconductivity in Kagome Systems with Mixed Edge Chiralities
• Uniaxial strain tuning of charge modulation and singularity in a kagome superconductor
• Vestigial singlet pairing in a fluctuating magnetic triplet superconductor: Applications to graphene moiré systems
• Self-consistent theory of $2\times 2$ pair density waves in kagome superconductors
• Low-Energy Electronic Structure in the Unconventional Charge-Ordered State of ScV${}_6$Sn${}_6$
• Electronic band structures of topological kagome materials
• Search for orbital magnetism in the kagome superconductor $\mathrm{Cs}{\mathrm{V}}_3\mathrm{S}{\mathrm{b}}_5$ using neutron diffraction
• Theory of charge-6e condensed phase in Kagome lattice superconductors
• Charge-4$e$ Superconductivity in a Hubbard model
• Electron correlations in the kagome flat band metal $\mathrm{CsC}{\mathrm{r}}_3\mathrm{S}{\mathrm{b}}_5$
• Pair-density-wave superconductivity: a microscopic model on 2D honeycomb lattice
• Frustrated Ising charge correlations in the kagome metal ScV${}_6$Sn${}_6$
• Quantum Oscillations Evidence for Topological Bands in Kagome Metal ScV6Sn6
• Exotic charge density waves and superconductivity on the Kagome Lattice
• Conventional Superconductivity in the Doped Kagome Superconductor Cs(V0.86Ta0.14)3Sb5 from Vortex Lattice Studies
• Cooper quartets in interacting hybrid superconducting systems
• Pair-breaking scattering interference as a mechanism for superconducting gap modulation
• Quantum-metric-induced giant and reversible nonreciprocal transport phenomena in chiral loop-current phases of kagome metals
• Electronic structure of $A$V${}_3$Sb${}_5$ kagome metals
• Quantifying magnetic field driven lattice distortions in kagome metals at the femto-scale using scanning tunneling microscopy
• Chiral pair density wave as a precursor of the pseudogap in kagomé superconductors
• High-order van Hove singularities and nematic instability in the kagome superconductor CsTi${}_3$Bi${}_5$
• Theories for charge-driven nematicity in kagome metals
• Andreev reflection in normal metal/charge-4e superconductor junctions
• Phase coherence of charge-$6e$ superconductors via a frustrated Kagome XY antiferromagnet
• Large Oscillatory Thermal Hall Effect in Kagome Metals
• Photoemission Insights to Electronic Orders in Kagome Superconductor AV3Sb5
• Interplay of superconductivity and charge-density-wave order in kagome materials
• Imaging half-unit-cell Cooper-pair density waves in monolayer 1T${}^{\prime }$-MoTe${}_2$
• Loop Current Order on the Kagome Lattice
• Thermomodulated intrinsic Josephson effect in Kagome CsV3Sb5
• Encoding innumerable charge density waves of FeGe into polymorphs of LiFe6Ge6
• Charge-density wave fluctuation driven composite order in the layered Kagome Metals
• Interplay of Charge Density Wave and Magnetism on the Kagomé Lattice
• Switchable chiral 2x2 pair density wave in pure CsV3Sb5
• Vestigial $d$-wave charge-$4e$ Superconductivity from Bidirectional Pair Density Waves
• Josephson diodes induced by the loop current states
• Spontaneous Lattice Distortion in the Spin-Triplet Superconductor Cu${}_x$Bi${}_2$Se${}_3$
• Recent progress in quantum spin liquids, fractional magnetization plateaus, and unconventional superconductivity in kagome lattices
• Finite-momentum pairing and superlattice superconductivity in valley-imbalanced rhombohedral graphene
• Nanoscale strain manipulation of smectic susceptibility in kagome superconductors
• Phase-sensitive evidence for pair density waves in a kagome superconductor
• Pair-density-wave phase of strongly interacting electrons on the triangular lattice: A variational Monte Carlo study
• Phenomenological Ginzburg-Landau theory for triple-Q magnetic orders on a hexagonal lattice
• Inter-Layer Correlation of Loop Current Charge Density Wave on the Bilayer Kagomé Lattice
• Topological in-gap chiral edge states in superconducting Haldane model with spin-orbit coupling
• Orbital current signature using neutron diffraction
• Topological pair density waves in kagome superconductors
• SU(4) Kondo Lattice in Semiconductor Moiré Materials
• Spontaneous emergence of altermagnetism in the single-orbital extended Hubbard model
• Spin-triplet pair density wave superconductors
• Fermion quartets on the square lattice
• Enhanced Coupling of Superconductivity and Evolution of Gap Structure in CsV3Sb5 through Ta Doping