Dirac magnons in a honeycomb lattice quantum XY magnet CoTiO3

Abstract

The discovery of massless Dirac electrons in graphene and topological Dirac-Weyl materials has prompted a broad search for bosonic analogues of such Dirac particles. Recent experiments have found evidence for Dirac magnons above an Ising-like ferromagnetic ground state in a two-dimensional (2D) kagome lattice magnet and in the van der Waals layered honeycomb crystal CrI${}_3$, and in a 3D Heisenberg magnet Cu${}_3$TeO${}_6$. Here we report on our inelastic neutron scattering investigation on large single crystals of a stacked honeycomb lattice magnet CoTiO${}_3$, which is part of a broad family of ilmenite materials. The magnetically ordered ground state of CoTiO${}_3$ features ferromagnetic layers of Co${}^{2+}$, stacked antiferromagnetically along the $c$-axis. We discover that the magnon dispersion relation exhibits strong easy-plane exchange anisotropy and hosts a clear gapless Dirac cone along the edge of the 3D Brillouin zone. Our results establish CoTiO${}_3$ as a model pseudospin-$1/2$ material to study interacting Dirac bosons in a 3D quantum XY magnet.

7 pages, 5 figures; Supplemental Materials Available upon request

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Cited by in corpus (60)

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• Kitaev Spin Liquid in 3d Transition Metal Compounds
• Antiferromagnetic Kitaev interaction in $J_\rm{eff}=1/2$ cobalt honeycomb materials Na${}_3$Co${}_2$SbO${}_6$ and Na${}_2$Co${}_2$TeO${}_6$
• Materials design of Kitaev spin liquids beyond the Jackeli-Khaliullin mechanism
• Topological insulators and semimetals in classical magnetic systems
• Interaction-stabilized topological magnon insulator in ferromagnets
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• Spin-Space Groups and Magnon Band Topology
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• Topological magnon insulator spin excitations in the two-dimensional ferromagnet CrBr${}_3$
• XY magnetism, Kitaev exchange, and long-range frustration in the $J_{\mathrm{eff}}=1/2$ honeycomb cobaltates
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• Spin-waves in 2D honeycomb lattice $XXZ$-type van der Waals antiferromagnet CoPS${}_3$
• Giant effective magnetic moments of chiral phonons from orbit-lattice coupling
• Thermal Evolution of Dirac Magnons in the Honeycomb Ferromagnet CrBr${}_3$
• Massless Dirac magnons in the two dimensional van der Waals honeycomb magnet CrCl3
• Dirac magnons, nodal lines, and nodal plane in elemental gadolinium
• Lattice dynamics and spontaneous magnetodielectric effect in ilmenite CoTiO${}_3$
• Gaps in Topological Magnon Spectra: Intrinsic vs. Extrinsic Effects
• Spin dynamics in the Kitaev model with disorder: Quantum Monte Carlo study of dynamical spin structure factor, magnetic susceptibility, and NMR relaxation rate
• Magnetic phase diagram and magneto-elastic coupling of NiTiO3
• Spin-Orbit Exciton in a Honeycomb Lattice Magnet CoTiO${}_3$: Revealing Link Between Rare Earth and Transition Metal Magnetism
• Dipolar spin waves in uniaxial easy-axis antiferromagnets: A natural topological nodal-line semimetal
• Observation of spin-wave moiré edge and cavity modes in twisted magnetic lattices
• Interacting topological Dirac magnons
• Identifying, and constructing, complex magnon band topology
• Magneto-structural coupling in ilmenite-type NiTiO${}_3$: a combined diffraction and dilatometry study
• Proximate Dirac spin liquid in honeycomb lattice $J_1$-$J_3$ XXZ model: Numerical study and application to cobaltates
• An overview of the spin dynamics of antiferromagnetic Mn${}_5$Si${}_3$
• Introducing the monoclinic polymorph of the Kitaev magnet Na${}_2$Co${}_2$TeO${}_6$
• Magnon Landau levels in the strained antiferromagnetic honeycomb nanoribbons
• Dirac cones and mass terms in bosonic spectra
• Dirac Hamiltonians for bosonic spectra
• Diffusive Excitonic Bands from Frustrated Triangular Sublattice in a Singlet-Ground-State System
• Quantum Monte Carlo study of honeycomb antiferromagnets under a triaxial strain
• Spin Waves and Dirac Magnons in a Honeycomb Lattice Zig-zag Antiferromagnet BaNi2(AsO4)2
• Scattering phenomena for spin transport in Kitaev spin liquid
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• The role of magnetoelastic coupling and magnetic anisotropy in MnTiO${}_3$
• Out-of-plane magnetic anisotropy in bulk ilmenite ${\text{CoTiO}}_3$
• Spin excitations in the kagome-lattice metallic antiferromagnet Fe${}_{0.89}$Co${}_{0.11}$Sn
• Krein-unitary Schrieffer-Wolff transformation and band touchings in bosonic Bogoliubov-de Gennes and other Krein-Hermitian Hamiltonians
• Pulling order back from the brink of disorder: Observation of a nodal line spin liquid and fluctuation stabilized order in K${}_2$IrCl${}_6$
• Dipolar spin-waves and tunable band gap at the Dirac points in the 2D magnet ErBr3
• Control of spin waves by spatially modulated strain
• Bond-dependent interactions and ill-ordered state in the honeycomb cobaltate BaCo${}_2$(AsO${}_4$)${}_2$
• Contrasting magnetothermal conductivity in sibling Co-based honeycomb-lattice antiferromagnets
• Impact of gapped spin-orbit excitons on low energy pseudospin exchange interactions
• Dirac Magnon in Honeycomb Lattice Magnet NiTiO3
• Spin waves in layered antiferromagnets with honeycomb structure
• Phonon topology and winding of spectral weight in graphite
• Amplifying the antiferromagnetic spin Seebeck effect through topological magnons
• Coexistence of static and dynamic local magnetic fields in an S = 3/2 honeycomb lattice antiferromagnet Co2Te3O8
• Predicted versatile topological nodal magnons in Tb-based icosahedral quasicrystal 1/1 approximants
• Multiple topological phases of magnons induced by Dzyaloshinskii-Moriya and pseudodipolar anisotropic exchange interactions in Kagome ferromagnets
• Fate of Bosonic Topological Edge Modes in the Presence of Many-Body Interactions
• Crystalline water intercalation into the Kitaev honeycomb cobaltate Na${}_2$Co${}_2$TeO${}_6$
• Dirac magnons pairing via pumping
• Band topology and dynamic multiferroicity induced from dynamical Dzyaloshinskii-Moriya interactions in centrosymmetric lattices