Origin of competing charge density waves in kagome metal ScV${}_6$Sn${}_6$

Abstract

Understanding competing charge density wave (CDW) orders in the bilayer kagome metal ScV${}_6$Sn${}_6$ remains challenging. Experimentally, upon cooling, short-range order with wave vector ${\mathbf{q}}_2=(\frac{1}{3},\frac{1}{3},\frac{1}{2})$ forms, which is subsequently suppressed by the condensation of long-range ${\mathbf{q}}_3=(\frac{1}{3},\frac{1}{3},\frac{1}{3})$ CDW order at lower temperature. Theoretically, however, the ${\mathbf{q}}_2$ CDW is predicted as the ground state, leaving the CDW mechanism elusive. Here, using anharmonic phonon-phonon calculations combined with density functional theory, we predict a temperature-driven structural phase transitions from the high-temperature pristine phase to the ${\mathbf{q}}_2$ CDW, followed by the low-temperature ${\mathbf{q}}_3$ CDW, explaining experimental observations. We demonstrate that semi-core electron states stabilize the ${\mathbf{q}}_3$ CDW over the ${\mathbf{q}}_2$ CDW. Furthermore, we find that the out-of-plane lattice parameter controls the competing CDWs, motivating us to propose compressive bi-axial strain as an experimental protocol to stabilize the ${\mathbf{q}}_2$ CDW. Finally, we suggest Ge or Pb doping at the Sn site as another potential avenue to control CDW instabilities. Our work provides a full theory of CDWs in ScV${}_6$Sn${}_6$, rationalizing experimental observations and resolving earlier discrepancies between theory and experiment.

19 pages, 5 figures

References in corpus (48)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• High temperature fractional quantum Hall states
• CsV${}_3$Sb${}_5$: a ${\mathbb{Z}}_2$ topological kagome metal with a superconducting ground state
• Nearly-flat bands with nontrivial topology
• Discovery of unconventional chiral charge order in kagome superconductor KV3Sb5
• 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
• Superconductivity in the ${\mathbb{Z}}_2$ kagome metal KV${}_3$Sb${}_5$
• Double superconducting dome and triple enhancement of Tc in the kagome superconductor CsV3Sb5 under high pressure
• Three-dimensional charge density wave and robust zero-bias conductance peak inside the superconducting vortex core of a kagome superconductor CsV${}_3$Sb${}_5$
• Superconductivity and normal-state properties of kagome metal RbV3Sb5 single crystals
• Unusual competition of superconductivity and charge-density-wave state in a compressed topological kagome metal
• Analysis of Charge Order in the Kagome Metal $A$V${}_3$Sb${}_5$ ($A=$K,Rb,Cs)
• Discovery of charge density wave in a correlated kagome lattice antiferromagnet
• Kagome superconductors AV${}_3$Sb${}_5$ (A=K, Rb, Cs)
• Interaction-driven topological insulators on the kagome and the decorated honeycomb lattices
• Three-state nematicity and magneto-optical Kerr effect in the charge density waves in kagome superconductors
• The Stochastic Self-Consistent Harmonic Approximation: Calculating Vibrational Properties of Materials with Full Quantum and Anharmonic Effects
• Charge density wave in kagome lattice intermetallic ScV6Sn6
• Intertwined magnetism and charge density wave order in kagome FeGe
• Charge-order-assisted topological surface states and flat bands in the kagome superconductor CsV${}_3$Sb${}_5$
• Probing topological quantum matter with scanning tunnelling microscopy
• 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${}_6$
• Softening of a flat phonon mode in the kagome ScV${}_6$Sn${}_6$
• Competing charge-density wave instabilities in the kagome metal ScV${}_6$Sn${}_6$
• Abundant lattice instability in kagome metal ScV${}_6$Sn${}_6$
• Strong coupling nature of kagome superconductivity in LaRu${}_3$Si${}_2$
• Uniaxial ferromagnetism in the kagome metal TbV${}_6$Sn${}_6$
• Flat band separation and robust spin-Berry curvature in bilayer kagome metals
• Phonon promoted charge density wave in topological kagome metal ScV${}_6$Sn${}_6$
• GdV6Sn6: a Multi-carrier Metal with Non-magnetic 3d-electron Kagome Bands and 4f-electron Magnetism
• Nanoscale visualization and spectral fingerprints of the charge order in ScV6Sn6 distinct from other kagome metals
• Frustrated charge order and cooperative distortions in ScV6Sn6
• Tiny Sc allows the chains to rattle: Impact of Lu and Y doping on the charge density wave in ScV${}_6$Sn${}_6$
• Quantum oscillations revealing topological band in kagome metal ScV6Sn6
• Dynamics and Resilience of the Charge Density Wave in a bilayer kagome metal
• Monolayer Kagome Metals AV${}_3$Sb${}_5$
• Charge order above room-temperature in a prototypical kagome superconductor La(Ru${}_{1-x}$Fe${}_x$)${}_3$Si${}_2$
• Nonuniform grids for Brillouin zone integration and interpolation
• Phonon collapse and anharmonic melting of the 3D charge-density wave in kagome metals
• Order-by-disorder charge density wave condensation at $\text{q}=(\frac{1}{3},\frac{1}{3},\frac{1}{3})$ in kagome metal ScV${}_6$Sn${}_6$

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