Phonon promoted charge density wave in topological kagome metal ScV${}_6$Sn${}_6$

Abstract

Charge density wave (CDW) orders in vanadium-based kagome metals have recently received tremendous attention due to their unique properties and intricate interplay with exotic correlated phenomena, topological and symmetry-breaking states. However, the origin of the CDW order remains a topic of debate. The discovery of ScV${}_6$Sn${}_6$, a vanadium-based bilayer kagome metal exhibiting an in-plane $\sqrt{3}$ x $\sqrt{3}$ $\text{R}$30$°$ CDW order with time-reversal symmetry breaking, provides a novel platform to explore the underlying mechanism behind the unconventional CDW. Here, we combine high-resolution angle-resolved photoemission spectroscopy, Raman scattering measurements and density functional theory to investigate the electronic structures and phonon modes of ScV${}_6$Sn${}_6$ and their evolution with temperature. We identify topologically nontrivial Dirac surface states and multiple van Hove singularities (VHSs) in the vicinity of the Fermi level, with one VHS near the K point exhibiting nesting wave vectors in proximity to the $\sqrt{3}$ x $\sqrt{3}$ $\text{R}$30$°$ CDW wave vector. Additionally, Raman measurements indicate a strong intrinsic electron-phonon coupling in ScV${}_6$Sn${}_6$, as evidenced by the presence of a two-phonon mode and a large frequency amplitude mode. Our findings highlight the fundamental role of lattice degrees of freedom in promoting the CDW in ScV${}_6$Sn${}_6$ and provide important insights into the fascinating correlation phenomena observed in kagome metals.

References in corpus (26)

• CsV${}_3$Sb${}_5$: a ${\mathbb{Z}}_2$ topological kagome metal with a superconducting ground state
• Roton pair density wave and unconventional strong-coupling superconductivity in a topological kagome metal
• Cascade of correlated electron states in a kagome superconductor CsV3Sb5
• Unconventional Fermi surface instabilities in the Kagome Hubbard Model
• Time-reversal symmetry-breaking charge order in a kagome superconductor
• Charge density waves and electronic properties of superconducting kagome metals
• Chiral flux phase in the Kagome superconductor AV${}_3$Sb${}_5$
• Analysis of Charge Order in the Kagome Metal $A$V${}_3$Sb${}_5$ ($A=$K,Rb,Cs)
• Electronic instabilities of kagome metals: saddle points and Landau theory
• Rich Nature of Van Hove Singularities in Kagome Superconductor CsV${}_3$Sb${}_5$
• Complex charge density waves at Van Hove singularity on hexagonal lattices: Haldane-model phase diagram and potential realization in kagome metals ${\text{AV}}_3{\text{Sb}}_5$
• Interaction-driven topological insulators on the kagome and the decorated honeycomb lattices
• Charge density wave in kagome lattice intermetallic ScV6Sn6
• Doped Kagome System as Exotic Superconductor
• Theory of the charge-density wave in $A$V${}_3$Sb${}_5$ kagome metals
• Tunable nodal kagome superconductivity in charge ordered RbV3Sb5
• Anomalously Strong Near-Neighbor Attraction in Doped 1D Cuprate Chains
• Realizing Kagome Band Structure in Two-Dimensional Kagome Surface States of $R{V}_{6}S{n}_6$ ($R$=Gd,Ho)
• Study of the electronic properties of topological kagome metals YV${}_6$Sn${}_6$ and GdV${}_6$Sn${}_6$
• 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${}_5$
• Abundant lattice instability in kagome metal ScV${}_6$Sn${}_6$
• Optical spectroscopy and band structure calculations of structural phase transition in the Vanadium-based kagome metal ScV${}_6$Sn${}_6$
• Nanoscale visualization and spectral fingerprints of the charge order in ScV6Sn6 distinct from other kagome metals
• Observation of anomalous amplitude modes in the kagome metal CsV${}_3$Sb${}_5$

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• Persistent flat band splitting and strong selective band renormalization in a kagome magnet thin film
• Kagome Materials I: SG 191, ScV${}_6$Sn${}_6$. Flat Phonon Soft Modes and Unconventional CDW Formation: Microscopic and Effective Theory
• Realization of Kagome Kondo lattice
• Low-Energy Electronic Structure in the Unconventional Charge-Ordered State of ScV${}_6$Sn${}_6$
• Electronic band structures of topological kagome materials
• Instability of the charge density wave in Kagome magnet FeGe
• Ground-state magnetic structures of topological kagome metals RV${}_6$Sn${}_6$ (R = Tb, Dy, Ho, Er)
• Origin of anomalous magnetotransport in kagome superconductors AV${}_3$Sb${}_5$ (A=K,Rb,Cs)
• Frustrated Ising charge correlations in the kagome metal ScV${}_6$Sn${}_6$
• Origin of competing charge density waves in kagome metal ScV${}_6$Sn${}_6$
• Orbital selective commensurate modulations of the local density of states in ScV6Sn6 probed by nuclear spins
• Competing Lattice Instability and Magnetism on the Surface of Kagome Metals
• Kagome Metal GdNb${}_6$Sn${}_6$: A 4d Playground for Topological Magnetism and Electron Correlations
• Discovery of an Intermediate Nematic State in a Bilayer Kagome Metal ScV6Sn6
• Incommensurate and commensurate antiferromagnetic orders in the kagome compound UV${}_6$Sn${}_6$
• Magnetic order and physical properties of the Kagome metal UNb${}_6$Sn${}_6$
• Pressure suppresses the density wave order in kagome metal LuNb${}_6$Sn${}_6$
• Anomalous Nernst Effect and Its Implications for Time-Reversal Symmetry Breaking in Kagome Metal ScV6Sn6
• Altermagnetism in an interacting model of Kagome materials
• Beyond kagome: $p$-bands in kagome metals
• Synergistic doping and stabilization of magnetically tunable LnTi${}_3$(Sb,Sn)${}_4$ (Ln:Ce--Gd) kagome metals
• Revealing magnetism in the distorted kagome $R$Ti${}_3$Bi${}_4$ ($R$ = Nd, Sm, Gd) via ARPES and XMCD
• Interplay of phonons, intertwined density waves, and induced spin density wave in trilayer nickelates Pr4-xLaxNi3O10
• Structural modulation, physical properties, and electronic band structure of the kagome metal UCr${}_6$Ge${}_6$