Spin Fluctuations in Sr${}_{1.8}$La${}_{0.2}$RuO${}_4$

Abstract

We use inelastic neutron scattering to study spin fluctuations in Sr${}_{1.8}$La${}_{0.2}$RuO${}_4$, where Lanthanum doping triggers a Lifshitz transition by pushing the van Hove singularity in the $\gamma$ band to the Fermi energy. Strong spin fluctuations emerge at an incommensurate wave vector ${\mathbf{Q}}_{ic}=(0.3,0.3)$, corresponding to the nesting vector between $\alpha$ and $\beta$ Fermi sheets. The incommensurate antiferromagnetic fluctuations shift toward $(0.25,0.25)$ with increasing energy up to $\sim 110$ meV. By contrast, scatterings near the ferromagnetic wave vectors $\mathbf{Q}=(1,0)$ and $(1,1)$ remain featureless at all energies. This contradicts the weak-coupling perspective that suggests a sharp enhancement of ferromagnetic susceptibility due to the divergence of density of states in the associated $\gamma$ band. Our findings imply that ferromagnetic fluctuations in Sr${}_2$RuO${}_4$ and related materials do not fit into the weak-coupling paradigm, but instead are quasi-local fluctuations induced by Hund's coupling. This imposes significant constraints for the pairing mechanism involving spin fluctuations.

arXiv comment7 pages, 4 figures

References in corpus (45)

• Time-Reversal Symmetry Breaking Superconductivity in Sr2RuO4
• High Resolution Polar Kerr Effect Measurements of Sr2RuO4: Evidence for Broken Time Reversal Symmetry in the Superconducting State
• Evaluation of Spin-Triplet Superconductivity in Sr2RuO4
• Pronounced drop of ${}^{17}$O NMR Knight shift in superconducting state of Sr${}_2$RuO${}_4$
• Chiral Superconductors
• Ferromagnetic spin fluctuation induced superconductivity in Sr_2RuO_4
• Strong Peak in $T_c$ of Sr${}_2$RuO${}_4$ Under Uniaxial Pressure
• Evidence for incommensurate spin fluctuations in Sr_2RuO_4
• Competitions in layered ruthenates: ferro- vs. antiferromagnetism and triplet vs. singlet pairing
• A polarized neutron-scattering study of the Cooper-pair moment in Sr2RuO4
• Upper limit on spontaneous supercurrents in Sr${}_2$RuO${}_4$
• Magnetic ground state of FeSe
• p-wave and d-wave superconductivity in quasi-two-dimensional metals
• Hidden quasi one-dimensional superconductivity in Sr${}_2$RuO${}_4$
• Limits on Superconductivity-Related Magnetization in Sr${}_2$RuO${}_4$ and PrOs${}_4$Sb${}_{12}$ from Scanning SQUID Microscopy
• Split superconducting and time-reversal symmetry-breaking transitions, and magnetic order in Sr${}_2$RuO${}_4$ under uniaxial stress
• Reduction of the ${}^{17}$O Knight shift in the Superconducting State and the Heat-up Effect by NMR Pulses on Sr${}_2$RuO${}_4$
• Thermodynamic Evidence for a Two-Component Superconducting Order Parameter in Sr${}_2$RuO${}_4$
• Spin-triplet superconductivity due to antiferromagnetic spin-fluctuation in Sr_2RuO_4
• Inelastic neutron scattering study of magnetic excitations in Sr${}_2$RuO${}_4$
• Ultrasound evidence for a two-component superconducting order parameter in Sr${}_2$RuO${}_4$
• Stabilizing Even-Parity Chiral Superconductivity in Sr${}_2$RuO${}_4$
• A proposal for reconciling diverse experiments on the superconducting state in Sr2RuO4
• Resistivity in the Vicinity of a Van Hove Singularity: Sr${}_2$RuO${}_4$ Under Uniaxial Pressure
• Strain Control of Fermiology and Many-Body Interactions in Two-Dimensional Ruthenates
• Knight Shift and Leading Superconducting Instability From Spin Fluctuations in Sr2RuO4
• Momentum Resolved Superconducting Energy Gaps of Sr${}_2$RuO${}_4$ from Quasiparticle Interference Imaging
• Incommensurate magnetic ordering in Sr_2Ru_(1-x)Ti_xO_4
• Reduction of the spin susceptibility in the superconducting state of Sr2RuO4 observed by polarized neutron scattering
• Spin fluctuations in Sr2RuO4 from polarized neutron scattering: implications for superconductivity
• Unsplit superconducting and time reversal symmetry breaking transitions in Sr${}_2$RuO${}_4$ under hydrostatic pressure and disorder
• Magnetic response of Sr${}_2$RuO${}_4$: quasi-local spin fluctuations due to Hund's coupling
• Superconducting order of ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$ from a three-dimensional microscopic model
• Angular dependence of the upper critical field of Sr2RuO4
• Anisotropy of the incommensurate fluctuations in Sr2RuO4: a study with polarized neutrons
• Anisotropic critical magnetic fluctuations in the ferromagnetic superconductor UCoGe
• Inelastic neutron scattering study of the magnetic fluctuations in Sr${}_2$RuO${}_4$
• Rigid-Band Shift of the Fermi Level in a Strongly Correlated Metal: Sr(2-y)La(y)RuO(4)
• Spin Density Wave Fluctuations and p-wave Pairing in Sr2RuO4
• Magnetic-Field Tunable Intertwined Checkerboard Charge Order and Nematicity in the Surface Layer of Sr${}_2$RuO${}_4$
• Horizontal Line Nodes in Sr2RuO4 Proved by Spin Resonance
• Spin gap and L modulated intensity at the low-energy incommensurate magnetic fluctuations in the superconducting state of Sr2RuO4
• Neutron scattering studies on spin fluctuations in Sr${}_2$RuO${}_4$
• Absence of a large superconductivity-induced gap in magnetic fluctuations of Sr2RuO4
• Coexistence of ferromagnetic and stripe-type antiferromagnetic spin fluctuations in YFe${}_2$Ge${}_2$

Cited by in corpus (1)

• Conditions for orbital selective altermagnetism in Sr${}_2$RuO${}_4$: tight binding model, similarities with cuprates and implications on superconductivity