Microscopic Study of Electronic and Magnetic Properties for Ir Oxide

Abstract

The exact diagonalization and the variational cluster approximation (VCA) are used to study the nature of a novel Mott insulator induced by a strong spin-orbit coupling for a two-dimensional three-band Hubbard model consisting of the $t_{2g}$ manifold of $5d$ orbitals. To characterize the ground state, we introduce a local Kramer's doublet which can represent a state with effective angular momentum $J_{\mathrm{eff}}=|\mathbf{S}-\mathbf{L}|=1/2$ as well as spin $S=1/2$. Our systematic study of the pseudo-spin structure factor defined by the Kramer's doublet shows that the $J_{\mathrm{eff}}=1/2$ Mott insulator is smoothly connected to the $S=1/2$ Mott insulator. Using the Kramer's doublet as a variational state for the VCA, we examine the one-particle excitations for the Mott insulating phase. These results are compared with recent experiments on Sr${}_2$IrO${}_4$.

4 pages, 3 figures

References in corpus (4)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Variational cluster approach to correlated electron systems in low dimensions
• Microscopic study of spin-orbit-induced Mott insulator in Ir oxides
• Spin-Orbit Integrated Ground State and Magnetic Anisotropy in Sr${}_2$IrO${}_4$

Cited by in corpus (3)

• Monte Carlo study of an unconventional superconducting phase in Ir-oxide J_{eff}=1/2 Mott insulators induced by carrier doping
• Theoretical study of insulating mechanism in multi-orbital Hubbard models with a large spin-orbit coupling: Slater versus Mott scenario in Sr${}_2$IrO${}_4$
• Variational cluster approach to thermodynamic properties of interacting fermions at finite temperatures: A case study of the two-dimensional single-band Hubbard model at half filling