Multiple Energy Scales and Anisotropic Energy Gap in the Charge-Density-Wave Phase of Kagome Superconductor CsV3Sb5

Abstract

Kagome metals AV3Sb5 (A = K, Rb, and Cs) exhibit superconductivity at 0.9-2.5 K and charge-density wave (CDW) at 78-103 K. Key electronic states associated with the CDW and superconductivity remain elusive. Here, we investigate low-energy excitations of CsV3Sb5 by angle-resolved photoemission spectroscopy. We found an energy gap of 70-100 meV at the Dirac-crossing points of linearly dispersive bands, pointing to an importance of spin-orbit coupling. We also found a signature of strongly Fermi-surface and momentum-dependent CDW gap characterized by the larger energy gap of maximally 70 meV for a band forming a saddle point around the M point, the smaller (0-18 meV) gap for a band forming massive Dirac cones, and a zero gap at the Gamma-centered electron pocket. The observed highly anisotropic CDW gap which is enhanced around the M point signifies an importance of scattering channel connecting the saddle points, laying foundation for understanding the nature of CDW and superconductivity in AV3Sb5.

10 pages, 9 figures

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• Cascade of correlated electron states in a kagome superconductor CsV3Sb5
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• Charge density waves and electronic properties of superconducting kagome metals
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• Valence Bond Solids and Their Quantum Melting in Hard-Core Bosons on the Kagome Lattice
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• Charge-density-wave-induced bands renormalization and energy gaps in a kagome superconductor RbV3Sb5
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Cited by in corpus (94)

• Topological kagome magnets and superconductors
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• Kagome superconductors AV${}_3$Sb${}_5$ (A=K, Rb, Cs)
• Twofold symmetry of $c$-axis resistivity in topological kagome superconductor CsV${}_3$Sb${}_5$ with in-plane rotating magnetic field
• Three-state nematicity and magneto-optical Kerr effect in the charge density waves in kagome superconductors
• Quantum states and intertwining phases in kagome materials
• AV${}_3$Sb${}_5$ Kagome Superconductors: Progress and Future Directions
• Tunable nodal kagome superconductivity in charge ordered RbV3Sb5
• Emergence of new van Hove singularities in the charge density wave state of a topological kagome metal RbV3Sb5
• Mechanism of exotic density-wave and beyond-Migdal unconventional superconductivity in kagome metal AV3Sb5 (A=K, Rb, Cs)
• Quantum transport evidence of topological band structures of kagome superconductor CsV3Sb5
• 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
• Possible star-of-David pattern charge density wave with additional modulation in the kagome superconductor CsV${}_3$Sb${}_5$
• Charge-Density-Wave-Induced Peak-Dip-Hump Structure and the Multiband Superconductivity in a Kagome Superconductor CsV${}_3$Sb${}_5$
• 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
• Tuning the competition between superconductivity and charge order in kagome superconductor Cs(V1-xNbx)3Sb5
• No observation of chiral flux current in the topological kagome metal CsV${}_3$Sb${}_5$
• Anomalous thermoelectric effects and quantum oscillations in the kagome metal CsV${}_3$Sb${}_5$
• Observation of Flat Band, Dirac Nodal Lines and Topological Surface States in Kagome Superconductor CsTi${}_3$Bi${}_5$
• Tuning the van Hove singularities in AV${}_3$Sb${}_5$ (A = K, Rb, Cs) via pressure and doping
• Observation of electronic nematicity driven by three-dimensional charge density wave in kagome lattice KV${}_3$Sb${}_5$
• Testing Electron-phonon Coupling for the Superconductivity in Kagome Metal $\mathrm{Cs}{\mathrm{V}}_3\mathrm{S}{\mathrm{b}}_5$
• Order-disorder Peierls instability in the kagome metal (Cs,Rb)V${}_3$Sb${}_5$
• 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
• Anomalous thermal Hall effect and anomalous Nernst effect of CsV${}_3$Sb${}_5$
• Optical study of RbV${}_3$Sb${}_5$: Multiple density-wave gaps and phonon anomalies
• The effect of the interlayer ordering on the Fermi surface of Kagome superconductor CsV${}_3$Sb${}_5$ revealed by quantum oscillations
• Three-dimensional energy gap and origin of charge-density wave in kagome superconductor KV3Sb5
• Electrically controlled superconductor-insulator transition and giant anomalous Hall effect in kagome metal CsV3Sb5 nanoflakes
• First-principles study on the double-dome superconductivities in kagome material CsV${}_3$Sb${}_5$ under pressure
• Carrier Injection and Manipulation of Charge-Density Wave in Kagome Superconductor CsV3Sb5
• Origin of Charge Density Wave in Layered Kagome Metal CsV${}_3$Sb${}_5$
• Emergent nematicity and intrinsic vs. extrinsic electronic scattering processes in the kagome metal CsV${}_3$Sb${}_5$
• Fermiology and Origin of Tc Enhancement in a Kagome Superconductor Cs(V1-xNbx)3Sb5
• Gapless excitations inside the fully gapped kagome superconductors AV${}_3$Sb${}_5$
• Dynamical Study of the Origin of the Charge Density Wave in $A$V${}_3$Sb${}_5$ ($A=$K, Rb, Cs) Compounds
• Magneto-Seebeck effect and ambipolar Nernst effect in CsV${}_3$Sb${}_5$ superconductor
• Spectroscopic Evidence for a Three-Dimensional Charge Density Wave in Kagome Superconductor CsV${}_3$Sb${}_5$
• Van Hove tuning of AV3Sb5 kagome metals under pressure and strain
• Multidome superconductivity in charge density wave kagome metals
• Electronic properties of correlated kagomé metals AV${}_3$Sb${}_5$(A = K, Rb, Cs): A perspective
• Polarity-dependent charge-density wave in a kagome superconductor CsV3Sb5
• 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${}_5$
• Surface-termination-dependent electronic states in kagome superconductors AV3Sb5 (A = K, Rb, Cs) studied by micro-ARPES
• Structural instability and charge modulations in the Kagome superconductor $A$V${}_3$Sb${}_5$
• Distinct band reconstructions in kagome superconductor CsV${}_3$Sb${}_5$
• Charge density wave and superconductivity in the kagome metal CsV${}_3$Sb${}_5$ around a pressure-induced quantum critical point
• Electrical and thermal transport properties of kagome metals $A$Ti${}_3$Bi${}_5$ ($A$ = Rb, Cs)
• Effects of Nb Doping on the Charge-Density Wave and Electronic Correlations in the Kagome Metal Cs(V${}_{1-x}$Nb${}_x$)${}_3$Sb${}_5$
• Direct Observation of Collective Modes of the Charge Density Wave in the Kagome Metal CsV${}_3$Sb${}_5$
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• 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
• Tilted Dirac cones and topological transitions in strained kagome lattices
• Kagome metals
• Kagome Materials I: SG 191, ScV${}_6$Sn${}_6$. Flat Phonon Soft Modes and Unconventional CDW Formation: Microscopic and Effective Theory
• Quantum Oscillations in kagome metals CsTi3Bi5 and RbTi3Bi5
• Violation of Emergent Rotational Symmetry in the Hexagonal Kagome Superconductor CsV3Sb5
• Observation of anomalous amplitude modes in the kagome metal CsV${}_3$Sb${}_5$
• Electronic structure and spin-lattice relaxation in superconducting vortex states on the kagome lattice near van Hove filling
• AV${}_3$Sb${}_5$ kagome superconductors: a review with transport measurements
• Emergence of Quantum Confinement in Topological Kagome Superconductor CsV${}_3$Sb${}_5$ family
• Origin of anomalous magnetotransport in kagome superconductors AV${}_3$Sb${}_5$ (A=K,Rb,Cs)
• Impact of the orbital current order on the superconducting properties of the kagome superconductors
• 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
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• Interplay between Chiral Charge Density Wave and Superconductivity in Kagome Superconductors: A Self-consistent Theoretical Analysis
• Electrical and thermal transport properties of kagome metals AV${}_3$Sb${}_5$ (A=K, Rb, Cs)
• Observation of Fermi-surface-dependent anisotropic Cooper pairing in kagome superconductor CsV3Sb5
• Electronic structure of $A$V${}_3$Sb${}_5$ kagome metals
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• Evidence for reduced periodic lattice distortion within the Sb-terminated surface layer of the kagome metal CsV${}_3$Sb${}_5$
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• Infrared spectroscopy study of kagome material CsTi${}_3$Bi${}_5$
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• Study on fluctuations of interface-enhanced superconductivity in ultrathin FeSe/SrTiO3 by the Nernst effect
• Electronic inhomogeneity in Cs- and Sb-terminated surfaces of CsV${}_3$Sb${}_5$ probed by scanning photoemission spectromicroscopy
• Time-Resolved Photoemission Spectroscopy of Quantum Materials Using High Harmonic Generation: Probing Electron-Phonon Interactions and Non-Equilibrium Dynamics
• The possible frustrated superconductivity in the kagome superconductors
• Microscopic origin of period-four stripe charge-density-wave in kagome metal CsV${}_3$Sb${}_5$
• Classification of mass terms in kagome semimetals
• Enhanced Coupling of Superconductivity and Evolution of Gap Structure in CsV3Sb5 through Ta Doping
• Hexagonal-to-base-centered-orthorhombic $4Q$ charge density wave order in kagome metals KV${}_3$Sb${}_5$, RbV${}_3$Sb${}_5$, and CsV${}_3$Sb${}_5$