Spin-orbit excitons and electronic configuration of the $5d^4$ insulator Sr$_3$Ir$_2$O$_7$F$_2$

Zach Porter; Paul M. Sarte; Thorben Petersen; Mary H. Upton; Liviu Hozoi; Stephen D. Wilson

doi:10.1103/PhysRevB.106.115140

paper

Spin-orbit excitons and electronic configuration of the $5 d^{4}$ insulator Sr $_{3}$ Ir $_{2}$ O $_{7}$ F $_{2}$

arXiv:2206.04721 · doi:10.1103/PhysRevB.106.115140

Abstract

Here we report on the low-energy excitations within the paramagnetic spin-orbit insulator Sr $_{3}$ Ir $_{2}$ O $_{7}$ F $_{2}$ studied via resonant inelastic X-ray scattering, \textit{ab initio} quantum chemical calculations, and model-Hamiltonian simulations. This material is a unique $d^{4}$ Ir $^{5 +}$ analog of Sr $_{3}$ Ir $_{2}$ O $_{7}$ that forms when F ions are intercalated within the SrO layers spacing the square lattice IrO $_{6}$ bilayers of Sr $_{3}$ Ir $_{2}$ O $_{7}$ . Due to the large distortions about the Ir $^{5 +}$ ions, our computations demonstrate that a large single-ion anisotropy yields an $S$ =1 ( $L \approx$ 1, $J \approx$ 0) ground state wave function. Weakly coupled, excitonic modes out of the $S_{z}$ =0 ground state are observed and are well-described by a phenomenological spin-orbit exciton model previously developed for $3 d$ and $4 d$ transition metal ions. The implications of our results regarding the interpretation of previous studies of hole-doped iridates close to $d^{4}$ fillings are discussed.

6 pages, 3 figures

Spin-orbit excitons and electronic configuration of the $5 d^{4}$ insulator Sr $_{3}$ Ir $_{2}$ O $_{7}$ F $_{2}$

Abstract

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Spin-orbit excitons and electronic configuration of the 5d4 insulator Sr3​Ir2​O7​F2​

Abstract

References in corpus (10)

Cited by in corpus (2)

Spin-orbit excitons and electronic configuration of the $5 d^{4}$ insulator Sr $_{3}$ Ir $_{2}$ O $_{7}$ F $_{2}$