Spin-orbit excitations and electronic structure of the putative Kitaev magnet $\alpha$-RuCl${}_3$

Abstract

Mott insulators with strong spin-orbit coupling have been proposed to host unconventional magnetic states, including the Kitaev quantum spin liquid. The 4$d$ system $\alpha$-RuCl${}_3$ has recently come into view as a candidate Kitaev system, with evidence for unusual spin excitations in magnetic scattering experiments. We apply a combination of optical spectroscopy and Raman scattering to study the electronic structure of this material. Our measurements reveal a series of orbital excitations involving localized total angular momentum states of the Ru ion, implying that strong spin-orbit coupling and electron-electron interactions coexist in this material. Analysis of these features allows us to estimate the spin-orbit coupling strength, as well as other parameters describing the local electronic structure, revealing a well-defined hierarchy of energy scales within the Ru $d$ states. By comparing our experimental results with density functional theory calculations, we also clarify the overall features of the optical response. Our results demonstrate that $\alpha$-RuCl${}_3$ is an ideal material system to study spin-orbit coupled magnetism on the honeycomb lattice.

7 pages, 4 figures, v2: revised figures and discussion, matches published version

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Cited by in corpus (114)

• Proximate Kitaev Quantum Spin Liquid Behaviour in α-RuCl${}_3$
• Neutron tomography of magnetic Majorana fermions in a proximate quantum spin liquid
• Models and Materials for Generalized Kitaev Magnetism
• Challenges in Design of Kitaev Materials: Magnetic Interactions from Competing Energy Scales
• Physics of the Kitaev model: fractionalization, dynamical correlations, and material connections
• Evidence for a Field-induced Quantum Spin Liquid in $\alpha$-RuCl${}_3$
• Spin-orbit excitation energies, anisotropic exchange, and magnetic phases of honeycomb RuCl3
• Crystal structure and magnetism in $\alpha$-RuCl3: an ab-initio study
• Phase Diagram of $\alpha$-RuCl${}_3$ in an in-plane Magnetic Field
• Gapless Spin Excitations in the Field-Induced Quantum Spin Liquid Phase of alpha-RuCl3
• Spin-wave excitations evidencing the Kitaev interaction in single crystalline $\alpha$-RuCl${}_3$
• Recent progress on correlated electron systems with strong spin-orbit coupling
• Microscopic mechanism for higher-spin Kitaev model
• Kitaev interactions in the Co honeycomb antiferromagnets Na${}_3$Co${}_2$SbO${}_6$ and Na${}_2$Co${}_2$TeO${}_6$
• Dynamics of the Kitaev-Heisenberg Model
• Relation between Kitaev magnetism and structure in $\alpha$-RuCl${}_3$
• Theoretical investigation of the magnetic dynamics in $\alpha$-RuCl${}_3$
• Theory of the field-revealed Kitaev spin liquid
• Approximately quantized thermal Hall effect of chiral liquids coupled to phonons
• J${}_{eff}$ description of the honeycomb Mott insulator $\alpha$-RuCl${}_3$
• Magnetic field induced quantum phases in a tensor network study of Kitaev magnets
• Proximate ferromagnetic state in the Kitaev model material $\alpha$-RuCl${}_3$
• Ultralow-temperature thermal conductivity of the Kitaev honeycomb magnet $\alpha$-RuCl${}_3$ across the field-induced phase transition
• Electronic properties of α-RuCl3 in proximity to graphene
• Two-dimensional spin liquid behaviour in the triangular-honeycomb antiferromagnet TbInO${}_3$
• Electronic Structure of the Kitaev Material $\alpha$-${\text{RuCl}}_3$ Probed by Photoemission and Inverse Photoemission Spectroscopies
• Optically Driven Magnetic Phase Transition of Monolayer RuCl3
• Unveiling Magnetic Interactions of Ruthenium Trichloride via Constraining Direction of Orbital moments: Potential Routes to Realize Quantum Spin Liquid
• Possible Structural Transformation and Enhanced Magnetic Fluctuations in Exfoliated $\alpha$-RuCl${}_3$
• Resonant inelastic X-ray scattering response of the Kitaev honeycomb model
• Identification of Magnetic Interactions and High-field Quantum Spin Liquid in $\alpha$-RuCl${}_3$
• ARPES study of the Kitaev Candidate $\alpha$-RuCl${}_3$
• Toward Kitaev's sixteenfold way in a honeycomb lattice model
• Quantum spin liquid at finite temperature: proximate dynamics and persistent typicality
• Two Dimensional Antiferromagnetic Chern Insulator NiRuCl6
• Pressure-tuned magnetic interactions in honeycomb Kitaev materials
• The range of non-Kitaev terms and fractional particles in RuCl${}_3$
• High-pressure magnetization and NMR studies on $\alpha$-RuCl${}_3$
• Giant effective magnetic moments of chiral phonons from orbit-lattice coupling
• Van Hove singularity in the magnon spectrum of the antiferromagnetic quantum honeycomb lattice
• Detuning the Honeycomb of $\alpha$-RuCl${}_3$: Pressure-Dependent Optical Studies Reveal Broken Symmetry
• Electronically highly cubic conditions for Ru in alpha-RuCl3
• Theory of the Kitaev model in a [111] magnetic field
• Tensor network wavefunction of $S=1$ Kitaev spin liquids
• Variational study of the Kitaev-Heisenberg-Gamma model
• The Heart of Entanglement: Chiral, Nematic, and Incommensurate Phases in the Kitaev-Gamma Ladder in a Field
• Electronic and phonon excitations in α-RuCl${}_3$
• Crystal field splitting, local anisotropy, and low energy excitations in the quantum magnet YbCl${}_3$
• Magnetic ordering with an XY-like anisotropy in the honeycomb lattice iridates ZnIrO${}_3$ and MgIrO${}_3$ synthesized via a metathesis reaction
• Electronic and magnetic properties of the RuX${}_3$ (X=Cl, Br, I) family: Two siblings -- and a cousin?
• Vison Crystals in an Extended Kitaev Model on the Honeycomb Lattice
• Ordered states in the Kitaev-Heisenberg model: From 1D chains to 2D honeycomb
• Field induced magnon excitation and in gap absorption of Kitaev candidate RuCl3
• From a quasimolecular band insulator to a relativistic Mott insulator in $t_{2g}^5$ systems with a honeycomb lattice structure
• Magnetic anisotropy of the alkali iridate Na${}_2$IrO${}_3$ at high magnetic fields: evidence for strong ferromagnetic Kitaev correlations
• Resonant inelastic x-ray scattering study of $\alpha$-RuCl${}_3$: a progress report
• Thermal Hall signatures of non-Kitaev spin liquids in honeycomb Kitaev materials
• Kitaev Quantum Spin Liquids
• Exact resummation of the Holstein-Primakoff expansion and differential equation approach to operator square-roots
• Edge magnetization and spin transport in an SU(2)-symmetric Kitaev spin liquid
• Probing spinon nodal structures in three-dimensional Kitaev spin liquids
• Local nuclear and magnetic order in the two-dimensional spin glass, Mn${}_{0.5}$Fe${}_{0.5}$PS${}_3$
• Observing spin fractionalization in the Kitaev spin liquid via temperature evolution of indirect resonant inelastic x-ray scattering
• Multiple Spin-Orbit Excitons and the Electronic Structure of $\alpha$-RuCl${}_3$
• Further insights into the thermodynamics of the Kitaev honeycomb model
• A computational method to estimate spin-orbital interaction strength in solid state systems
• Thermal anyon interferometry in phonon-coupled Kitaev spin liquids
• Role of the spin-orbit coupling in the Kugel-Khomskii model on the honeycomb lattice
• Fingerprints of quantum spin ice in Raman scattering
• Anisotropy as a diagnostic test for distinct tensor network wavefunctions of integer and half-integer spin Kitaev quantum spin liquids
• Kitaev Spin Liquid Candidate OsxCl3 Comprised of Honeycomb Nano-Domains
• Evidence for magnetic fractional excitations in a Kitaev quantum-spin-liquid candidate $\alpha$-RuCl${}_3$
• Field stability of Majorana spin liquids in antiferromagnetic Kitaev models
• Non-Kitaev spin liquids in Kitaev materials
• Extent of frustration in the classical Kitaev-$\Gamma$ model via bond anisotropy
• Tunneling spectroscopic signatures of charge doping and associated Mott transition in $\alpha$-RuCl${}_3$ in proximity to graphite
• Local spin structure of the $\alpha$-RuCl${}_3$ honeycomb-lattice magnet observed via muon spin rotation/relaxation
• SU($N$) spin-wave theory: Application to spin-orbital Mott insulators
• Field-induced Kitaev multipolar liquid in spin-orbit coupled $d^2$ honeycomb Mott insulators
• Sub-gap optical response across the structural phase transition in van der Waals layered α-RuCl${}_3$
• Testing Ising Topological Order in $\alpha$-RuCl${}_3$ Under In-Plane Magnetic Fields
• Spin dynamics of counterrotating Kitaev spirals via duality
• Acoustic phonon dispersion of $\alpha$-RuCl${}_3$
• Low temperature enhancement of ferromagnetic Kitaev correlations in α-RuCl3
• Light-induced magnetization driven by interorbital charge motion in a spin-orbit assisted Mott insulator alpha-RuCl3
• Phonon Dynamics in the Generalized Kitaev Spin Liquid
• Differentiable programming tensor networks for Kitaev magnets
• Spin liquid like Raman signatures in hyperkagome iridate Na${}_4$Ir${}_3$O${}_8$
• Magnetic-field Induced Topological Transitions and Thermal Conductivity in a Generalized Kitaev Model
• Electronic structure of $\mathbf{\alpha }$-RuCl${}_3$ by fixed-node and fixed-phase diffusion Monte Carlo methods
• Kitaev quasiparticles in a proximate spin liquid: A many-body localization perspective
• Dielectric Evidence for Possible Type-II Multiferroicity in alpha-RuCl3
• Spin waves and stability of zigzag order in the Hubbard model with spin-dependent hopping terms - Application to the honeycomb lattice compounds $\mathrm{N}{\mathrm{a}}_2\mathrm{Ir}{\mathrm{O}}_3$ and $\alpha -\mathrm{RuC}{\mathrm{l}}_3$
• Nonequilibrium dynamics of $\alpha$-RuCl${}_3$ -- a time-resolved magneto-optical spectroscopy study
• Non-local features of the spin-orbit exciton in Kitaev materials
• Efficient Method for Prediction of Meta-stable/Ground Multipolar Ordered States and its Application in Monolayer $\alpha$-\ce{RuX3} (X=Cl,I)
• Universal excitonic superexchange in spin-orbit-coupled Mott insulators
• Mott Gap Softening Coinciding with Spin Correlations Collapse in a-RuCl3
• Electron quasi-itinerancy intertwined with quantum order by disorder in pyrochlore iridate magnetism
• Optical contrast analysis of α-RuCl${}_3$ nanoflakes on oxidized silicon wafers
• Ground-state phase diagram of anisotropically interacting Heisenberg-$\Gamma$ models on a honeycomb lattice
• Thermal decomposition of the Kitaev material $\alpha$-RuCl${}_3$ and its influence on low-temperature behavior
• Understanding the magnetic interactions of the zig-zag honeycomb lattice: Application to $\alpha$-RuCl${}_3$
• First-principles study of bulk stacking, $J_{\mathrm{eff}}$ picture, magnetic Hamiltonian, $g$ factors, and structural distortions of $\alpha$-RuCl${}_3$
• Strain-induced Landau levels of Majorana fermions in an anisotropically interacting Kitaev model on a honeycomb lattice
• Spin-phonon coupling and thermal Hall effect in the Kitaev model
• Robustness of Vacancy-Bound Non-Abelian Anyons in the Kitaev Model in a Magnetic Field
• Photoinduced Pseudospin Polarization in a Three-Orbital Hubbard Model
• Pseudoscalar U(1) spin liquids in $\alpha$-RuCl${}_3$
• Non-Loudon-Fleury Raman scattering in spin-orbit coupled Mott insulators
• The Role of the Third Dimension in Searching Majorana Fermions in $\alpha$-RuCl${}_3$ via Phonons
• Vortex creation and control in the Kitaev spin liquid by local bond modulations
• Direct Evidence for Fermi Statistics from Proximity to the Kitaev Spin Liquid in RuCl3
• Ground state of the staggered Heisenberg-$\Gamma$ honeycomb model in a magnetic field