Interplay between Hund's coupling and spin-orbit interaction on elementary excitations in Sr2IrO4

Abstract

We study the elementary excitations in 5d transition metal oxideSr${}_2$IrO${}_4$ by calculating the particle-hole Green's function within the random phase approximation on an antiferromagnetic ground state in the two-dimensional multi-orbital Hubbard model. The obtained magnetic excitations of bound states show a characteristic dispersion in consistent with the experiments. In addition, two new types of excitations are found due to the interplay between spin-orbit interaction and Hund's coupling: a magnetic excitation as a bound state, which has energy gap at the $\Gamma$ point, and an exciton as a resonant mode in the continuum of electron-hole pair creation.

6 pages, 3 figures, Latex, final version, to be published in Journal of the Physical Society of Japan

References in corpus (10)

• 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
• On the Origin of Zigzag Magnetic Order in Iridium Oxide Na2IrO3
• Twisted Hubbard Model for Sr2IrO4: Magnetism and Possible High Temperature Superconductivity
• Monte Carlo study of an unconventional superconducting phase in Ir-oxide J_{eff}=1/2 Mott insulators induced by carrier doping
• The magnetic and crystal structures of Sr2IrO4: A neutron diffraction study
• Microscopic study of spin-orbit-induced Mott insulator in Ir oxides
• Electronic structures of layered perovskite Sr2MO4 (M=Ru, Rh, and Ir)
• Magnetic couplings, optical spectra, and spin-orbit exciton in 5d electron Mott insulator Sr2IrO4
• Magnetic excitation in resonant inelastic x-ray scattering of Sr${}_2$IrO${}_4$: A localized spin picture

Cited by in corpus (8)

• Square Lattice Iridates
• 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
• Analysis of resonant inelastic x-ray scattering from Sr${}_2$IrO${}_4$ in an itinerant-electron approach
• Collective excitations in Na${}_2$IrO${}_3$
• Possible superconductivity induced by a large spin-orbit coupling in carrier doped iridium oxide insulators: A weak coupling approach
• Cooper Pairing in A Doped 2D Antiferromagnet with Spin-Orbit Coupling
• Pseudo-spin rotation symmetry breaking by Coulomb interaction terms in spin-orbit coupled systems
• Coupled spin-orbital fluctuations in a three orbital model for $4d$ and $5d$ oxides with electron fillings $n=3,4,5$ -- Application to $\mathrm{NaOs}{\mathrm{O}}_3$, $\mathrm{C}{\mathrm{a}}_2\mathrm{Ru}{\mathrm{O}}_4$, and $\mathrm{S}{\mathrm{r}}_2\mathrm{Ir}{\mathrm{O}}_4$