Charge-order-assisted topological surface states and flat bands in the kagome superconductor CsV${}_3$Sb${}_5$

Abstract

The diversity of emergent phenomena in quantum materials often arises from the interplay between different physical energy scales or broken symmetries. Cooperative interactions among them are rare; however, when they do occur, they often stabilize fundamentally new ground states or phase behaviors. For instance, a pair density wave can form when the superconducting order parameter borrows spatial periodical variation from charge order; a topological superconductor can arise when topologically nontrivial electronic states proximitize with or participate in the formation of the superconducting condensate. Here, we report spectroscopic evidence for a unique synergy of topology and correlation effects in the kagome superconductor CsV${}_3$Sb${}_5$ - one where topologically nontrivial surface states are pushed below the Fermi energy (E${}_F$) by charge order, making the topological physics active near E${}_F$ upon entering the superconducting state. Flat bands are observed, indicating that electron correlation effects are also at play in this system. Our results reveal the peculiar electronic structure of CsV${}_3$Sb${}_5$, which holds the potential for realizing Majorana zero modes and anomalous superconducting states in kagome lattices. They also establish CsV${}_3$Sb${}_5$ as a unique platform for exploring the cooperation between the charge order, topology, correlation effects and superconductivity.

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• Visualizing the periodic modulation of Cooper pairing in a severely underdoped cuprate
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Cited by in corpus (72)

• Cascade of correlated electron states in a kagome superconductor CsV3Sb5
• Electronic Nature of Charge Density Wave and Electron-Phonon Coupling in Kagome Superconductor KV${}_3$Sb${}_5$
• Rotation symmetry breaking in the normal state of a kagome superconductor KV3Sb5
• Rich Nature of Van Hove Singularities in Kagome Superconductor CsV${}_3$Sb${}_5$
• Kagome superconductors AV${}_3$Sb${}_5$ (A=K, Rb, Cs)
• Quantum states and intertwining phases in kagome materials
• AV${}_3$Sb${}_5$ Kagome Superconductors: Progress and Future Directions
• Chern Fermi pocket, topological pair density wave, and charge-4e and charge-6e superconductivity in kagome superconductors
• Charge order landscape and competition with superconductivity in kagome metals
• Tunable Topological Dirac Surface States and Van Hove Singularities in Kagome Metal GdV${}_6$Sn${}_6$
• Coexistence of Tri-Hexagonal and Star-of-David Pattern in the Charge Density Wave of the Kagome Superconductor AV${}_3$Sb${}_5$
• A unique van Hove singularity in kagome superconductor CsV${}_{3-x}$Ta${}_x$Sb${}_5$ with enhanced superconductivity
• Observation of Flat Band, Dirac Nodal Lines and Topological Surface States in Kagome Superconductor CsTi${}_3$Bi${}_5$
• Observation of electronic nematicity driven by three-dimensional charge density wave in kagome lattice KV${}_3$Sb${}_5$
• Nodeless superconductivity in kagome metal CsV${}_3$Sb${}_5$ with and without time reversal symmetry breaking
• Electronic nematicity without charge density waves in titanium-based kagome metal
• Loop-current charge density wave driven by long-range Coulomb repulsion on the kagome lattice
• Tunable van Hove singularity without structural instability in Kagome metal CsTi${}_3$Bi${}_5$
• Gapless excitations inside the fully gapped kagome superconductors AV${}_3$Sb${}_5$
• Commensurate-to-incommensurate transition of charge-density-wave order and a possible quantum critical point in pressurized kagome metal CsV${}_3$Sb${}_5$
• Dynamical Study of the Origin of the Charge Density Wave in $A$V${}_3$Sb${}_5$ ($A=$K, Rb, Cs) Compounds
• Nanoscale visualization and spectral fingerprints of the charge order in ScV6Sn6 distinct from other kagome metals
• Emergence of large quantum oscillation frequencies in thin flakes of the kagome superconductor CsV${}_3$Sb${}_5$
• Spectroscopic Evidence for a Three-Dimensional Charge Density Wave in Kagome Superconductor CsV${}_3$Sb${}_5$
• Correlated Electronic Structure and Incipient Flat Bands of the Kagome Superconductor CsCr3Sb5
• Small Fermi pockets intertwined with charge stripes and pair density wave order in a kagome superconductor
• Electronic Landscape of Kagome Superconductors $\text{A}$V${}_3$Sb${}_5$ ($\text{A}$ = K, Rb, Cs) from Angle-Resolved Photoemission Spectroscopy
• Superconducting, topological and transport properties of kagome metals CsTi${}_3$Bi${}_5$ and RbTi${}_3$Bi${}_5$
• Charge fluctuations above $T_{\mathrm{CDW}}$ revealed by glasslike thermal transport in kagome metals $A$V${}_3$Sb${}_5$ ($A$ = K, Rb, Cs)
• Dirac Nodal Lines and Nodal Loops in a Topological Kagome Superconductor CsV${}_3$Sb${}_5$
• Anomalous Hall effect and two-dimensional Fermi surfaces in the charge-density-wave state of kagome metal RbV${}_3$Sb${}_5$
• Record-high Mobility and Extreme Magnetoresistance on Kagome-lattice in Compensated Semimetal Ni3In2S2
• Distinct band reconstructions in kagome superconductor CsV${}_3$Sb${}_5$
• Electrical and thermal transport properties of kagome metals $A$Ti${}_3$Bi${}_5$ ($A$ = Rb, Cs)
• Electronic Correlations and Evolution of the Charge-Density Wave in the Kagome Metals $A$V${}_3$Sb${}_5$ ($A$ = K, Rb, Cs)
• An unconventional platform for two-dimensional Kagome flat bands on semiconductor surfaces
• Topological superconductivity and large spin Hall effect in the kagome family Ti6X4 (X = Bi, Sb, Pb, Tl, In)
• Multiband effects in thermoelectric and electrical transport properties of kagome superconductors $A$V${}_3$Sb${}_5$ ($A$ = K, Rb, Cs)
• Majorana corner states on the dice lattice
• FeGe as a building block for the kagome 1:1, 1:6:6, and 1:3:5 families: hidden d-orbital decoupling of flat band sectors, effective models and interaction Hamiltonians
• Emergent topological quantum orbits in the charge density wave phase of kagome metal CsV${}_3$Sb${}_5$
• Kagome metals
• Diverse electronic landscape of the kagome metal YbTi3Bi4
• Quasidisorder Induced Topology
• Similarities and Differences in the Fermiology of Kagome Metals AV${}_3$Sb${}_5$ (A=K, Rb, Cs) Revealed by Shubnikov-de Haas Oscillations
• Two elementary band representation model, Fermi surface nesting, and surface topological superconductivity in $A$V${}_3$Sb${}_5$ ($A=\text{K, Rb, Cs}$)
• Electron correlations in the kagome flat band metal $\mathrm{CsC}{\mathrm{r}}_3\mathrm{S}{\mathrm{b}}_5$
• AV${}_3$Sb${}_5$ kagome superconductors: a review with transport measurements
• Emergence of Quantum Confinement in Topological Kagome Superconductor CsV${}_3$Sb${}_5$ family
• Two-dimensional phase diagram of the charge density wave in doped CsV${}_3$Sb${}_5$
• Revealing the orbital origins of exotic electronic states with Ti substitution in kagome superconductor CsV3Sb5
• Kagome materials $A$V${}_3$Sb${}_5$ ($A$=K,Rb,Cs): pairing symmetry and pressure-tuning studies
• Topological electronic structure and electronic nematicity in candidate kagome superconductors, ATi${}_3$Bi${}_5$ (A = Rb, Cs)
• Electrical and thermal transport properties of kagome metals AV${}_3$Sb${}_5$ (A=K, Rb, Cs)
• Complete miscibility amongst AV${}_3$Sb${}_5$ kagome superconductors: design of mixed A-site AV${}_3$Sb${}_5$ (A: K, Rb, Cs) alloys
• Tuning electronic pairing by uniaxial strain in kagome lattices
• Fully-gapped superconductivity with rotational symmetry breaking in pressurized kagome metal CsV${}_3$Sb${}_5$
• Origin of competing charge density waves in kagome metal ScV${}_6$Sn${}_6$
• Quantum Phase Transition as a Promising Route to Enhance the Critical Current in Kagome Superconductor CsV${}_3$Sb${}_5$
• Discovery of a new phase in thin flakes of KV${}_3$Sb${}_5$ under pressure
• Infrared spectroscopy study of kagome material CsTi${}_3$Bi${}_5$
• van Hove Singularity-Driven Emergence of Multiple Flat Bands in Kagome Superconductors
• Fidelity and variability in the interlayer electronic structure of the kagome superconductor CsV3Sb5
• Unconventional superconductivity in Sc${}_2$Ir${}_{4-x}$Si${}_x$ by spin-orbit coupling driven flat band
• Evidence of Mott Insulator with Thermally Induced Melting Behavior in Kagome Compound Nb3Cl8
• Topological Aspects of Dirac Fermions in a Kagomé Lattice
• Many-body electronic structure in pyrochlore superconductor CsBi2 and spin liquid Pr2Ir2O7
• Symmetry-broken ground state and phonon mediated superconductivity in Kagome CsV${}_3$Sb${}_5$
• Nodeless superconductivity and topological nodal states in molybdenum carbide
• Majorana edge states in s-wave kagome superconductors with Rashba interaction
• Kekulé order from diffuse nesting near higher-order Van Hove points
• Kagome edge states under lattice termination, spin-orbit coupling, and magnetic order