Fingerprints of spin-orbital physics in cubic Mott insulators: Magnetic exchange interactions and optical spectral weights

Abstract

The temperature dependence and anisotropy of optical spectral weights associated with different multiplet transitions is determined by the spin and orbital correlations. To provide a systematic basis to exploit this close relationship between magnetism and optical spectra, we present and analyze the spin-orbital superexchange models for a series of representative orbital-degenerate transition metal oxides with different multiplet structure. For each case we derive the magnetic exchange constants, which determine the spin wave dispersions, as well as the partial optical sum rules. The magnetic and optical properties of early transition metal oxides with degenerate $t_{2g}$ orbitals (titanates and vanadates with perovskite structure) are shown to depend only on two parameters, viz. the superexchange energy $J$ and the ratio $\eta$ of Hund's exchange to the intraorbital Coulomb interaction, and on the actual orbital state. In $e_g$ systems important corrections follow from charge transfer excitations, and we show that KCuF${}_3$ can be classified as a charge transfer insulator, while LaMnO${}_3$ is a Mott insulator with moderate charge transfer contributions. In some cases orbital fluctuations are quenched and decoupling of spin and orbital degrees of freedom with static orbital order gives satisfactory results for the optical weights. On the example of cubic vanadates we describe a case where the full quantum spin-orbital physics must be considered. Thus information on optical excitations, their energies, temperature dependence and anisotropy, combined with the results of magnetic neutron scattering experiments, provides an important consistency test of the spin-orbital models, and indicates whether orbital and/or spin fluctuations are important in a given compound.

34 pages, 16 figures

References in corpus (12)

• Orbital Physics in the Perovskite Ti Oxides
• Orbital-Spin Structure and Coupling to Lattice in RTiO${}_3$ with R=La,Pr,Nd and Sm
• Theory of optical spectral weights in Mott insulators with orbital degrees of freedom
• Valence bond crystal in a pyrochlore antiferromagnet with orbital degeneracy
• Structural, electronic, and magneto-optical properties of YVO${}_3$
• Orbital order in vanadium spinels
• Theory of orbital state and spin interactions in ferromagnetic titanates
• Lattice Distortion and Magnetic Ground State of YTiO${}_3$ and LaTiO${}_3$
• One-Dimensional Confinement and Enhanced Jahn-Teller Instability in LaVO${}_3$
• Microscopic modelling of doped manganites
• Entropy Driven Dimerization in a One-Dimensional Spin-Orbital Model
• Valence-Bond Crystal, and Lattice Distortions in a Pyrochlore Antiferromagnet with Orbital Degeneracy

Cited by in corpus (115)

• Orbital order and possible superconductivity in LaNiO3/LaMO3 superlattices
• Spin-Orbital Separation in the quasi 1D Mott-insulator Sr2CuO3
• Spin-orbital frustrations and anomalous metallic state in iron-pnictide superconductors
• Model for the Magnetic Order and Pairing Channels in Fe Pnictide Superconductors
• Interplay of p-d and d-d charge transfer transitions in rare-earth perovskite manganites
• Origin of the Verwey transition in magnetite: Group theory, electronic structure, and lattice dynamics study
• Combining DFT and Many-Body Methods to Understand Correlated Materials
• Fingerprints of spin-orbital entanglement in transition metal oxides
• Lattice Distortion and Magnetism of 3d-$t_{2g}$ Perovskite Oxides
• Low-energy Mott-Hubbard excitations in LaMnO_3 probed by optical ellipsometry
• Orbital-quenching-induced magnetism in Ba_2NaOsO_6
• Frustration and entanglement in the $t_{2g}$ spin--orbital model on a triangular lattice: valence--bond and generalized liquid states
• Competing Pairing Symmetries in a Generalized Two-Orbital Model for the Pnictides
• Hubbard exciton revealed by time-domain optical spectroscopy
• Microscopic origin of spin-orbital separation in Sr2CuO3
• Spectral properties of orbital polarons in Mott insulators
• Mott-Hubbard exciton in the optical conductivity of YTiO3 and SmTiO3
• Fingerprints of Spin-Orbital Physics in Crystalline O${}_2$
• Two-step stabilization of orbital order and the dynamical frustration of spin in the model charge-transfer insulator KCuF3
• Orbitally induced string formation in the spin-orbital polarons
• Optical response of ferromagnetic YTiO_3 studied by spectral ellipsometry
• Spin-Orbital Order Modified by Orbital Dilution in Transition Metal Oxides: From Spin Defects to Frustrated Spins Polarizing Host Orbitals
• One-dimensional orbital fluctuations and the exotic magnetic properties of YVO${}_3$
• Spin-orbital resonating valence bond liquid on a triangular lattice: Evidence from finite-cluster diagonalization
• Variational tensor network renormalization in imaginary time: Two-dimensional quantum compass model at finite temperature
• Microscopic origin of diagonal stripe phases in doped nickelates
• Fulde-Ferrell-Larkin-Ovchinnikov phase in the presence of pair hopping interaction
• Probing orbital fluctuations in RVO3 (R = Y, Gd, or Ce) by ellipsometry
• Vortex states in hole-doped iron-pnictide superconductors
• Magnetic properties of nanoscale compass-Heisenberg planar clusters
• Jahn-Teller effect in systems with strong on-site spin-orbit coupling
• Doping dependence of spin and orbital correlations in layered manganites
• Orbital order in La0.5Sr1.5MnO4: beyond a common local Jahn-Teller picture
• Exotic spin orders driven by orbital fluctuations in the Kugel-Khomskii model
• Validity and limitations of the superexchange model for the magnetic properties of Sr2IrO4 and Ba2IrO4 mediated by the strong spin-orbit coupling
• Spin-Density-Wave and Asymmetry of Coherence Peaks in iron-Pnictide Superconductors from a two-orbital model
• Entangled spin-orbital phases in the bilayer Kugel-Khomskii model
• Quantum phase transitions in exactly solvable one-dimensional compass models
• Topological Order in an Entangled SU(2)$\otimes$XY Spin-Orbital Ring
• Quantum phase transitions in a generalized compass chain with three-site interactions
• Charge density functional plus $U$ theory of LaMnO${}_3$: Phase diagram, electronic structure, and magnetic interaction
• Symmetry properties and spectra of the two-dimensional quantum compass model
• Overcoming the Sign Problem at Finite Temperature: Quantum Tensor Network for the Orbital $e_g$ Model on an Infinite Square Lattice
• Unraveling Orbital Correlations via Magnetic Resonant Inelastic X-ray Scattering
• Microscopic theory of electric polarization induced by skyrmionic order in GaV${}_4$S${}_8$
• Quasiparticle states around a nonmagnetic impurity in electron-doped iron-based superconductors with spin-density-wave order
• Mott-Hubbard versus charge-transfer behavior in LaSrMnO4 studied via optical conductivity
• Vortex state in iron-based superconductors with collinear antiferromagnetic cores
• Defect states and excitations in a Mott insulator with orbital degrees of freedom: Mott-Hubbard gap versus optical and transport gaps in doped systems
• Defect states and spin-orbital physics in doped vanadates Y1-xCaxVO3
• Anomalous multi-order Raman scattering in LaMnO_3: a signature of a quantum lattice effect in a Jahn-Teller crystal
• X-ray absorption study of the ferromagnetic Cu moment at the $\mathbf{YB}{\mathbf{a}}_2\mathbf{C}{\mathbf{u}}_3{\mathbf{O}}_7/\mathbf{L}{\mathbf{a}}_{2/3}\mathbf{C}{\mathbf{a}}_{1/3}\mathbf{Mn}{\mathbf{O}}_3$ interface and the variation of its exchange interaction with the Mn moment
• Magnetic states of the five-orbital Hubbard model for one-dimensional iron-based superconductors
• Spin-orbital order in LaMnO${}_3$: $d-p$ model study
• Defect-induced orbital polarization and collapse of orbital order in doped vanadium perovskites
• Formation of metallic magnetic clusters in a Kondo-lattice metal: Evidence from an optical study
• Temperature-dependent optical conductivity of layered LaSrFeO_4
• Fingerprints of spin-orbital polarons and of their disorder in the photoemission spectra of doped Mott insulators with orbital degeneracy
• Exotic Spin-Orbital Physics in Hybrid Oxides
• Mobile orbitons in Ca${}_2$CuO${}_3$: crucial role of the Hund's exchange
• Spin-orbital order in undoped manganite LaMnO3 at finite temperature
• Spin dynamics in electron-doped pnictide superconductors
• Frustration and Entanglement in Compass and Spin-Orbital Models
• Quantum entanglement in the one-dimensional spin-orbital SU(2)$\otimes XXZ$ model
• Charge and orbital order in transition metal oxides
• Dimensional crossover and the magnetic transition in electron doped manganites
• Phase diagram of doped BaFe${}_2$As${}_2$ superconductor under broken $C_4$ symmetry
• Skyrmionic order and magnetically induced polarization change in lacunar spinel compounds GaV${}_4$S${}_8$ and GaMo${}_4$S${}_8$: comparative theoretical study
• Photoemission of a doped Mott insulator: spectral weight transfer and qualitative Mott-Hubbard description
• Spin--orbital physics in transition metal oxides
• Orbital Symmetry and Orbital Excitations in High-$T_c$ Superconductors
• Spin-orbital entanglement near quantum phase transitions
• Spin, orbital and topological order in models of strongly correlated electrons
• Entanglement Driven Phase Transitions in Spin-Orbital Models
• Green's function variational approach to orbital polarons in KCuF3
• Mechanism of hole propagation in the orbital compass models
• From high-$T_c$ to low-$T_c$: Multi-orbital effects in transition metal oxides
• Topological Phases emerging from Spin-Orbital Physics
• Charge transfer model for the electronic structure of layered ruthenates
• Spin-orbital model of stoichiometric LaMnO${}_3$ with tetragonal distortions
• Magnetic resonance as an orbital state probe
• Locally tunable disorder and entanglement in the one-dimensional plaquette orbital model
• Orbiton-magnon interplay in the spin-orbital polarons of KCuF3 and LaMnO3
• Multiband $d-p$ model and self-doping in the electronic structure of Ba${}_2$IrO${}_4$
• Influence of multiplet structure on photoemission spectra of spin-orbit driven Mott insulators: application to $\mathbf{S}{\mathbf{r}}_2\mathbf{Ir}{\mathbf{O}}_4$
• Spin-orbit coupling and crystal-field splitting in Ti-doped Ca2RuO4 studied by ellipsometry
• Electronic correlations in vanadium chalcogenides: BaVSe3 versus BaVS3
• Raman scattering study and lattice-dynamics calculations in YTiO3: Precursor of the magnetic phase transition in the phonon anomalies
• Anomalous sharp peak in the London penetration depth induced by the nodeless-to-nodal superconducting transition in BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Spin-orbital-lattice entanglement in the ideal j=1/2 compound K${}_2$IrCl${}_6$
• Magnon dressing by orbital excitations in ferromagnetic planes of K${}_2$CuF${}_4$ and LaMnO${}_3$
• Magnetic and orbital correlations in a two-site molecule
• Low-energy V t2g orbital excitations in NdVO3
• Striped critical spin liquid in a spin-orbital entangled RVB state in a projected entangled-pair state representation
• Magnetic phases for two $t_{2g}$ holes with spin-orbit coupling and crystal field
• Spectral properties of spin-orbital polarons as a fingerprint of orbital order
• Softening of $dd$ excitation in the resonant inelastic x-ray scattering spectra as a signature of Hund's coupling in nickelates
• Tuning Crystal Field Potential by Orbital Dilution in $d^4$ Oxides
• Orbital Rotations induced by Charges of Polarons and Defects in Doped Vanadates
• Dispersion of orbital excitations in 2D quantum antiferromagnets
• Dynamics of photo-induced ferromagnetism in oxides with orbital degeneracy
• $d-p$ model and spin-orbital order in the vanadium perovskites
• Exotic Spin Order due to Orbital Fluctuations
• Spin-Orbital Liquid on a Triangular Lattice
• A possibility of high spin hole states in doped CoO${}_2$ layered systems
• Magnetic transitions in strong coupling expansions for nearly degenerate states
• Effects of single- and multi-substituted Zn ions in doped-122 type iron-based superconductors
• On the Neglect of Local Coulomb Interaction on Oxygens in Perovskites Described by the Multi-band $d-p$ Model
• Hund and pair-hopping signature in transport properties of degenerate nanoscale devices
• One-dimensional frustrated plaquette compass model: Nematic phase and spontaneous multimerization
• Optical detection of bond-dependent and frustrated spin in the two-dimensional cobalt-based honeycomb antiferromagnet Cu3Co2SbO6
• Orbital polaron in double exchange ferromagnets
• Orbital liquid in the $e_g$ orbital Hubbard model in $d=\infty$ dimensions
• Order in Quantum Compass and Orbital $e_g$ Models
• Mixed-State Effect on the Low-Energy Spin Dynamics in Optimally-doped Iron Pnictide Superconductors