Magnetic couplings, optical spectra, and spin-orbit exciton in 5d electron Mott insulator Sr2IrO4

Abstract

Based on the microscopic model including strong spin-orbit coupling, on-site Coulomb and Hund's interactions, as well as crystal field effects, we have investigated magnetic and optical properties of Sr2IrO4. Taking into account all possible intermediate state multiplets generated by virtual hoppings of electrons, we calculated the isotropic Heisenberg, pseudodipolar, and Dzyaloshinsky-Moriya coupling constants, which describe the experiment quite well. We have also evaluated the optical conductivity σ(ω) by employing the exact diagonalization method on small clusters, and obtained two peaks at \sim 0.5 and \sim 1.0 eV in agreement with experiment. The two peak structure of σ(ω) arises from the unusual Fano-type overlap between electron-hole continuum of the Jeff = 1/2 band and the intrasite spin-orbit exciton observed recently in Sr2IrO4 by resonant x-ray scattering.

5 pages, 4 figures, 1 table, Supplemental Material added, to be published in PRL

References in corpus (7)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• 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 $\infty$)
• Microscopic study of spin-orbit-induced Mott insulator in Ir oxides
• Electronic structures of layered perovskite Sr2MO4 (M=Ru, Rh, and Ir)
• Theory of optical spectral weights in Mott insulators with orbital degrees of freedom
• Ab initio determination of excitation energies and magnetic couplings in correlated, quasi two-dimensional iridates

Cited by in corpus (11)

• Monte Carlo study of an unconventional superconducting phase in Ir-oxide J_{eff}=1/2 Mott insulators induced by carrier doping
• Square Lattice Iridates
• Interplay between multipolar spin interactions, Jahn-Teller effect and electronic correlation in a $J_{eff}=\frac{3}{2}$ insulator
• Structural and metal-insulator transitions in rhenium based double perovskites via orbital ordering
• Dual gate control of bulk transport and magnetism in the spin-orbit insulator Sr2IrO4
• Engineering One-Dimensional Quantum Stripes from Superlattices of Two-Dimensional Layered Materials
• Magnetic properties of bilayer Sr${}_3$Ir${}_2$O${}_7$: role of epitaxial strain and oxygen vacancies
• Optical Signatures of Spin-Orbit Exciton in Bandwidth Controlled Sr${}_2$IrO${}_4$ Epitaxial Films via High-Concentration Ca and Ba Doping
• Electronic excitations in $\gamma$-Li${}_2$IrO${}_3$
• Analysis of resonant inelastic x-ray scattering from Sr${}_2$IrO${}_4$ in an itinerant-electron approach
• Optical Signature of a Crossover from Mott- to Slater-type Gap in Sr${}_2$Ir${}_{1-x}$Rh${}_x$O${}_4$