Spin excitations in metallic kagome lattice FeSn and CoSn

Abstract

In two-dimensional (2D) metallic kagome lattice materials, destructive interference of electronic hopping pathways around the kagome bracket can produce nearly localized electrons, and thus electronic bands that are flat in momentum space. When ferromagnetic order breaks the degeneracy of the electronic bands and splits them into the spin-up majority and spin-down minority electronic bands, quasiparticle excitations between the spin-up and spin-down flat bands should form a narrow localized spin-excitation Stoner continuum coexisting with well-defined spin waves in the long wavelengths. Here we report inelastic neutron scattering studies of spin excitations in 2D metallic Kagome lattice antiferromagnetic FeSn and paramagnetic CoSn, where angle resolved photoemission spectroscopy experiments found spin-polarized and nonpolarized flat bands, respectively, below the Fermi level. Although our initial measurements on FeSn indeed reveal well-defined spin waves extending well above 140 meV coexisting with a flat excitation at 170 meV, subsequent experiments on CoSn indicate that the flat mode actually arises mostly from hydrocarbon scattering of the CYTOP-M commonly used to glue the samples to aluminum holder. Therefore, our results established the evolution of spin excitations in FeSn and CoSn, and identified an anomalous flat mode that has been overlooked by the neutron scattering community for the past 20 years.

References in corpus (7)

• High temperature fractional quantum Hall states
• Fractional quantum Hall states at zero magnetic field
• Quantum Monte Carlo Impurity Solver for Cluster DMFT and Electronic Structure Calculations in Adjustable Base
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• Negative flat band magnetism in a spin-orbit coupled correlated kagome magnet
• Theoretical prediction of a strongly correlated Dirac metal
• Electron doping evolution of the anisotropic spin excitations in BaFe2-xNixAs2

Cited by in corpus (34)

• Topological kagome magnets and superconductors
• Discovery of charge density wave in a correlated kagome lattice antiferromagnet
• Intertwined magnetism and charge density wave order in kagome FeGe
• AV${}_3$Sb${}_5$ Kagome Superconductors: Progress and Future Directions
• Topological Quantum Materials with Kagome Lattice
• Damped Dirac magnon in a metallic kagome antiferromagnet FeSn
• Novel three-dimensional Fermi surface and electron-correlation-induced charge density wave in FeGe
• Magnetic interactions and possible structural distortion in kagome FeGe from first-principles study and symmetry analysis
• Competing itinerant and local spin interactions in kagome metal FeGe
• Emergence of flat bands and ferromagnetic fluctuations via orbital-selective electron correlations in Mn-based kagome metal
• Spin-charge-lattice coupling across the charge density wave transition in a Kagome lattice antiferromagnet
• Spin-polarized imaging of the antiferromagnetic structure and field-tunable bound states in kagome magnet FeSn
• Dirac fermions with plaquette interactions. III. SU(N) phase diagram with Gross-Neveu criticality and first-order phase transition
• Complex magnetic and spatial symmetry breaking from correlations in kagome flat bands
• \textit{Ab initio} study on spin fluctuations of itinerant kagome magnet FeSn
• 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
• Chiral and flat-band magnetic cluster excitations in a ferromagnetic kagome metal
• Persistent flat band splitting and strong selective band renormalization in a kagome magnet thin film
• Investigating the magneto-elastic properties in FeSn and Fe${}_3$Sn${}_2$ flat band metals
• Electronic band structures of topological kagome materials
• Orbital-selective effect of spin reorientation on the Dirac fermions in a non-charge-ordered kagome ferromagnet Fe${}_3$Ge
• Phononic drumhead surface state in distorted kagome compound RhPb
• Anomalous Electrical Transport in the Kagome Magnet YbFe${}_6$Ge${}_6$
• Spin waves and orbital contribution to ferromagnetism in a topological metal
• Spin excitations in the kagome-lattice metallic antiferromagnet Fe${}_{0.89}$Co${}_{0.11}$Sn
• Simultaneous development of antiferromagnetism and local symmetry breaking in a kagome magnet (Co${}_{0.45}$Fe${}_{0.55}$)Sn
• $T_3$Pb${}_{2}C{h}_2$ ($T$=Pd,Pt and $Ch$=S,Se) with transition metal kagome net: Dynamical properties, phonon nodal line, phonon surface states, and chiral phonons
• Spin-flop quasi metamagnetic, anisotropic magnetic, and electrical transport behavior of Ho substituted kagome magnet ErMn${}_6$Sn${}_6$
• Atomic bonding and electrical characteristics of two-dimensional graphene/boron nitride van der Waals heterostuctures with manufactured defects via binding energy and bond-charge model
• The "Sign problem" of the 3rd order anomalous Hall effect in topological magnetic materials
• Anisotropic response of defect bound states to magnetic field in epitaxial FeSn films
• Unconventional spin transport in strongly correlated kagome systems
• Magnetism of kagome metals $\left({\text{Fe}}_{1-x}{\text{Co}}_x\right)\text{Sn}$ studied by $\mu$SR
• Nature of magnetic exchange interactions in kagome antiferromagnets FeGe and FeSn