Persistent paramagnons deep in the metallic phase of Sr${}_{2-x}$La${}_x$IrO${}_4$

Abstract

We have studied the magnetic excitations of electron-doped Sr${}_{2-x}$La${}_x$IrO${}_4$ ($0\le x\le 0.10$) using resonant inelastic x-ray scattering (RIXS) at the Ir L${}_3$-edge. The long range magnetic order is rapidly lost with increasing $x$, but two-dimensional short-range order (SRO) and dispersive magnon excitations with nearly undiminished spectral weight persist well into the metallic part of the phase diagram. The magnons in the SRO phase are heavily damped and exhibit anisotropic softening. Their dispersions are well described by a pseudospin-1/2 Heisenberg model with exchange interactions whose spatial range increases with doping. We also find a doping-independent high-energy magnetic continuum, which is not described by this model. The spin-orbit excitons arising from the pseudospin-3/2 manifold of the Ir ions broaden substantially in the SRO phase, but remain largely separated from the low-energy magnons. Pseudospin-1/2 models are therefore a good starting point for the theoretical description of the low-energy magnetic dynamics of doped iridates.

6 pages, 4 figures

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• High-energy spin and charge excitations in electron-doped copper oxide superconductors
• Crystal growth and intrinsic magnetic behavior of Sr${}_2$IrO${}_4$
• Raman and fluorescence characteristics of resonant inelastic X-ray scattering from doped superconducting cuprates
• Itinerant effects and enhanced magnetic interactions in Bi-based multilayer cuprates
• Anisotropic softening of magnetic excitations in lightly electron doped Sr${}_2$IrO${}_4$

Cited by in corpus (60)

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• Mixing of $t_{2g}$-$e_g$ orbitals in 4d and 5d transition metal oxides
• Fingerprints of Kitaev physics in the magnetic excitations of honeycomb iridates
• Two-dimensional $J_{\mathrm{eff}}$ = 1/2 antiferromagnetic insulator unraveled from interlayer exchange coupling in artificial perovskite iridate superlattices
• Pseudospin-lattice coupling in the spin-orbit Mott insulator Sr2IrO4
• Superconductivity in high-$T_c$ and related strongly correlated systems from variational perspective: Beyond mean field theory
• Strain-engineering of the charge and spin-orbital interactions in Sr2IrO4
• Raman scattering study of vibrational and magnetic excitations in Sr${}_{2-x}$La${}_x$IrO${}_4$
• Unidirectional spin density wave state in metallic (Sr1-xLax)2IrO4
• Anisotropic exchange and spin-wave damping in pure and electron-doped Sr${}_2$IrO${}_4$
• Dispersive Magnetic and Electronic Excitations in Iridate Perovskites Probed with Oxygen $K$-Edge Resonant Inelastic X-ray Scattering
• The Jeff=1/2 antiferromagnet Sr2IrO4: A golden avenue toward new physics and functions
• Doping Evolution of Magnetic Order and Magnetic Excitations in (Sr${}_{1-x}$La${}_x$)${}_3$Ir${}_2$O${}_7$
• Novel spin-orbit coupling driven emergent states in iridate-based heterostructures
• Correlation effects and hidden spin-orbit entangled electronic order in parent and electron-doped iridates Sr${}_2$IrO${}_4$
• Effect of Cu${}^{2+}$ substitution in Spin-Orbit Coupled Sr${}_2$Ir${}_{1-x}$Cu${}_x$O${}_4$: Structure, magnetism and electronic properties
• Spectral functions of Sr${}_2$IrO${}_4$: theory versus experiment
• Theoretical study of the spin and charge dynamics of two-leg ladders as probed by resonant inelastic x-ray scattering
• Fractional spin excitations in the infinite-layer cuprate CaCuO${}_2$
• A unified theory of spin and charge excitations in high-$T_c$ cuprates: Quantitative comparison with experiment and interpretation
• Spin-gap and two-dimensional magnetic excitations in Sr2IrO4
• A Hubbard exciton fluid in a photo-doped antiferromagnetic Mott insulator
• Impurity-induced phonon thermal Hall effect in the antiferromagnetic phase of Sr2IrO4
• Magnetic excitations in a three-orbital model for the strongly spin-orbit coupled iridates: Effect of mixing between the J=1/2 and 3/2 sectors
• Non-local Coulomb correlations in pure and electron-doped ${\mathrm{Sr}}_2{\mathrm{IrO}}_4$: spectral functions, Fermi surface and pseudogap-like spectral weight distributions from oriented cluster dynamical mean field theory
• Description of resonant inelastic x-ray scattering in correlated metals
• Possibility to realize spin-orbit-induced correlated physics in iridium fluorides
• BaOsO${}_3$: A Hund's metal in the presence of strong spin-orbit coupling
• Spectroscopic evidence for electron-boson coupling in electron-doped Sr${}_2$IrO${}_4$
• Spin-wave gap collapse in Rh-doped Sr2IrO4
• Persistence of antiferromagnetic order upon La substitution in the $4d^4$ Mott insulator Ca${}_2$RuO${}_4$
• Robust spin and charge excitations throughout high-$T_c$-cuprate phase diagram from incipient Mottness
• Decoupling of static and dynamic criticality in a driven Mott insulator
• Magnetic excitations in hole-doped Sr2IrO4: A comparison with electron-doped cuprates
• Giant Spin Gap and Magnon Localization in the Disordered Heisenberg Antiferromagnet Sr2Ir1-xRuxO4
• Mott transition and collective charge pinning in electron doped Sr2IrO4
• Resonant inelastic x-ray scattering of magnetic excitations under pressure
• $J=1/2$ Pseudospins and $d$-$p$ Hybridization in the Kitaev Spin Liquid Candidates Ru$X_3$ ($X$ = Cl, Br, I)
• Strong anisotropy within a Heisenberg model in the J=1/2 insulating state of Sr2Ir0.8Ru0.2O4
• Magnetism and electrical transport in Y-doped layered iridate Sr${}_2$IrO${}_4$
• Coherent and incoherent bands in La and Rh doped Sr3Ir2O7
• Universal collective modes from strong electronic correlations: Modified $1/{\mathcal{N}}_f$ theory with application to high-$T_c$ cuprates
• Quasi-2D anomalous Hall Mott insulator of topologically engineered Jeff =1/2 electrons
• Carrier density crossover and quasiparticle mass enhancement in a doped 5$d$ Mott insulator
• Correlated motion of particle-hole excitations across the renormalized spin-orbit gap in $\mathrm{S}{\mathrm{r}}_2\mathrm{Ir}{\mathrm{O}}_4$
• Possible superconductivity induced by a large spin-orbit coupling in carrier doped iridium oxide insulators: A weak coupling approach
• Collective spin and charge excitations in the $t$-$J$-$U$ model of high-$T_c$ cuprates
• Spin-orbit excitons in a correlated metal: Raman scattering study of Sr2RhO4
• Spin and charge order in doped spin-orbit coupled Mott insulators
• Magnetism in artificial Ruddlesden-Popper iridates leveraged by structural distortions
• Anomalous Nodal Gap in a Doped Spin-1/2 Antiferromagnetic Mott Insulator
• Three-dimensional Stacking of Canted Antiferromagnetism and Pseudospin Current in Undoped Sr${}_2$IrO${}_4$: Symmetry Analysis and Microscopic Model Realization
• Coexistence of insulator-like paramagnon and metallic spin-orbit exciton modes in SrIrO${}_3$
• High-pressure floating zone crystal growth of Sr${}_2$IrO${}_4$
• Magnetic Excitations of a Half-Filled Tl-based Cuprate
• Electron-hole asymmetry of quantum collective excitations in high-$T_c$ copper oxides
• Fermi surface and pseudogap in highly doped Sr${}_2$IrO${}_4$
• Two dimensional electron gas in the $\delta$-doped iridates with strong spin-orbit coupling: La${}_{\delta }$Sr${}_2$IrO${}_4$
• Absence of temperature-dependent phonon anomalies in Sr2IrO4 and Sr3Ir2O7