Coexistence of insulator-like paramagnon and metallic spin-orbit exciton modes in SrIrO${}_3$

Abstract

We probe the spectrum of elementary excitations in SrIrO${}_3$ by using heterostructured [(SrIrO${}_3$)${}_m$/(SrTiO${}_3$)${}_l$] samples to approach the bulk limit. Our resonant inelastic x-ray scattering (RIXS) measurements at the Ir $L_3$-edge reveal a robust low-lying collective magnetic mode with an antiferromagnetic (AF) dispersion similar to the insulators Sr${}_2$IrO${}_4$ and Sr${}_3$Ir${}_2$O${}_7$, albeit with a large gap and much larger linewidth. At higher energies we find the spin-orbit exciton, also strongly broadened, but with an inverted dispersion and doubled periodicity that are controlled by the charge hopping. These results demonstrate that the AF paramagnon persists, somewhat counterintuitively, far into the metallic regime of the insulator-metal transition driven by the degree of confinement in the heterostructure. We conclude that these two excitations, which are contrasting but coexisting hallmarks of strong AF pseudospin and charge fluctuations in a spin-orbit-coupled Mott-Slater material, are properties intrinsic to the ground state of semimetallic perovskite SrIrO${}_3$.

References in corpus (51)

• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• Spin waves and electronic interactions in La2CuO4
• Bandwidth-Controlled Insulator-Metal Transition and Correlated Metallic State in 5$d$ Transition Metal Oxides Sr${}_{n+1}$Ir${}_n$O${}_{3n+1}$ ($n$=1, 2, and $\infty$)
• Isospin Dynamics in Sr2IrO4 : Forging Links to Cuprate Superconductivity
• Intense paramagnon excitations in a large family of high-temperature superconductors
• Crystal field splitting and correlation effect on the electronic structure of A2IrO3
• Interplay of Spin-Orbit Interactions, Dimensionality, and Octahedral Rotations in Semimetallic SrIrO${}_3$
• Engineering spin-orbital magnetic insulator by tailoring superlattices
• Microscopic study of spin-orbit-induced Mott insulator in Ir oxides
• Reduced effective spin-orbital degeneracy and spin-orbital ordering in paramagnetic transition metal oxides: Sr2IrO4 vs. Sr2RhO4
• Excitonic quasiparticles in a spin-orbit Mott insulator
• Giant Magnon Gap in Bilayer Iridate Sr3Ir2O7: Enhanced Pseudo-dipolar Interactions Near the Mott Transition
• Interplay between spin-orbit coupling and Hubbard interaction in SrIrO3 and related Pbnm perovskites
• Tuning Perpendicular Magnetic Anisotropy by Oxygen Octahedral Rotations in (La${}_{1-x}$Sr${}_x$MnO${}_3$)/(SrIrO${}_3$) Superlattices
• Anisotropic spin-orbit torque generation in epitaxial SrIrO3 by symmetry design
• Spin-orbit semimetal SrIrO${}_3$ in the two-dimensional limit
• Non-Fermi-liquid behavior in nearly ferromagnetic metallic SrIrO3 single crystals
• Linear-in temperature resistivity from an isotropic Planckian scattering rate
• Dispersive spin excitations in highly overdoped cuprates revealed by resonant inelastic x-ray scattering
• Dimensionality-driven metal-insulator-transition in spin-orbit coupled SrIrO${}_3$
• Persistent paramagnons deep in the metallic phase of Sr${}_{2-x}$La${}_x$IrO${}_4$
• Direct observation of the Dirac nodes lifting in semimetallic perovskite SrIrO3 thin films
• CaIrO3: a Spin-Orbit Mott Insulator Beyond the jeff = 1/2 Ground State
• Two-dimensional $J_{\mathrm{eff}}$ = 1/2 antiferromagnetic insulator unraveled from interlayer exchange coupling in artificial perovskite iridate superlattices
• Tuning Magnetic Coupling in Sr${}_2$IrO${}_4$ Thin Films with Epitaxial Strain
• Theory of Large Intrinsic Spin Hall Effect in Iridate Semimetals
• Evidence of quantum dimer excitations in Sr${}_3$Ir${}_2$O${}_7$
• Observation of spin-orbit excitations and Hund's multiplets in Ca${}_2$RuO${}_4$
• Slater Insulator in Iridate Perovskites with Strong Spin-Orbit Coupling
• Strain-engineering of the charge and spin-orbital interactions in Sr2IrO4
• Spin-Orbital Excitations in Ca${}_2$RuO${}_4$ Revealed by Resonant Inelastic X-ray Scattering
• Anisotropic damping of the spin fluctuations in doped La2-xSrxCuO4 studied by resonant inelastic x-ray scattering
• Spin-excitation anisotropy in the nematic state of detwinned FeSe
• Magnetic and electronic properties at the gamma-Al2O3/SrTiO3 interface
• Doping Evolution of Magnetic Order and Magnetic Excitations in (Sr${}_{1-x}$La${}_x$)${}_3$Ir${}_2$O${}_7$
• On the extraction of paramagnon excitations from resonant inelastic X-ray scattering experiments
• Structural properties and anisotropic electronic transport in SrIrO3 films
• Strange semimetal dynamics in SrIrO${}_3$
• Intra-layer doping effects on the high-energy magnetic correlations in NaFeAs
• Antiferromagnetic Excitonic Insulator State in Sr3Ir2O7
• Spin-gap and two-dimensional magnetic excitations in Sr2IrO4
• Strain-modulated Slater-Mott crossover of pseudospin-half square-lattice in (SrIrO3)1/ (SrTiO3)1 superlattices
• Paramagnon dispersion in $\beta$-FeSe observed by Fe $L$-edge resonant inelastic x-ray scattering
• Anomalous Magnetoresistance due to Longitudinal Spin Fluctuations in a Jeff = 1/2 Mott Semiconductor
• Spin-wave gap collapse in Rh-doped Sr2IrO4
• Anisotropic magnetic excitations and incipient Néel order in Ba(Fe${}_{1-x}$Mn${}_x$)${}_2$As${}_2$
• Simultaneous Metal-Insulator and Antiferromagnetic Transitions in Orthorhombic Perovskite Iridate Sr0.94Ir0.78O2.68 Single Crystals
• Isostructural Metal-Insulator Transition Driven by Dimensional-Crossover in SrIrO3 Heterostructures
• Magnetic excitations in hole-doped Sr2IrO4: A comparison with electron-doped cuprates
• Quasi-2D anomalous Hall Mott insulator of topologically engineered Jeff =1/2 electrons
• Spin-orbit excitons in a correlated metal: Raman scattering study of Sr2RhO4