Dispersive Magnetic and Electronic Excitations in Iridate Perovskites Probed with Oxygen $K$-Edge Resonant Inelastic X-ray Scattering

Abstract

Resonant inelastic X-ray scattering (RIXS) experiments performed at the oxygen-$K$ edge on the iridate perovskites {\SIOS} and {\SION} reveal a sequence of well-defined dispersive modes over the energy range up to $\sim 0.8$ eV. The momentum dependence of these modes and their variation with the experimental geometry allows us to assign each of them to specific collective magnetic and/or electronic excitation processes, including single and bi-magnons, and spin-orbit and electron-hole excitons. We thus demonstrated that dispersive magnetic and electronic excitations are observable at the O-$K$ edge in the presence of the strong spin-orbit coupling in the $5d$ shell of iridium and strong hybridization between Ir $5d$ and O $2p$ orbitals, which confirm and expand theoretical expectations. More generally, our results establish the utility of O-$K$ edge RIXS for studying the collective excitations in a range of $5d$ materials that are attracting increasing attention due to their novel magnetic and electronic properties. Especially, the strong RIXS response at O-$K$ edge opens up the opportunity for investigating collective excitations in thin films and heterostructures fabricated from these materials.

6 pages, 4 figures with supplementary material. Accepted by PRB Rapid Communications

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Cited by in corpus (11)

• Square Lattice Iridates
• Strain-engineering of the charge and spin-orbital interactions in Sr2IrO4
• Revisiting the Kitaev material candidacy of Ir4+ double perovskite iridates
• High-resolution resonant inelastic x-ray scattering study of the electron-phonon coupling in honeycomb $\alpha$-Li${}_2$IrO${}_3$
• Theoretical study of the spin and charge dynamics of two-leg ladders as probed by resonant inelastic x-ray scattering
• Spin and charge excitations in the correlated multiband metal Ca3Ru2O7
• Direct observation of oxygen polarization in Sr${}_2$IrO${}_4$ by O $K$-edge x-ray magnetic circular dichroism
• Spin-orbit-entangled electronic structure of Ba${}_2$CaOsO${}_6$ studied by O $K$-edge resonant inelastic X-ray scattering
• Spin-orbital-lattice entanglement in the ideal j=1/2 compound K${}_2$IrCl${}_6$
• Charge ordering in Ir dimers in the ground state of Ba${}_5$AlIr${}_2$O${}_{11}$
• Observation of spin-conserving two-spinon continuum in the $S$=1/2 antiferromagnetic chain system Sr${}_2$CuO${}_3$ using Cu $K$-edge resonant inelastic x-ray scattering