Spin-orbital state induced by strong spin-orbit coupling

Abstract

To clarify a crucial role of a spin-orbit coupling in the emergence of novel spin-orbital states in $5d$-electron compounds such as Sr${}_2$IrO${}_4$, we investigate ground state properties of a $t_{2g}$-orbital Hubbard model on a square lattice by Lanczos diagonalization. In the absence of the spin-orbit coupling, the ground state is spin singlet. When the spin-orbit coupling is strong enough, the ground state turns into a weak ferromagnetic state. The weak ferromagnetic state is a singlet state in terms of an effective total angular momentum. Regarding the orbital state, we find the so-called complex orbital state, in which real $xy$, $yz$, and $zx$ orbital states are mixed with complex coefficients.

4 pages, 3 figures, Proceedings of SCES2011 (August 29 - September 3, 2011, Cambridge, UK)

References in corpus (6)

• 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
• Twisted Hubbard Model for Sr2IrO4: Magnetism and Possible High Temperature Superconductivity
• Microscopic study of spin-orbit-induced Mott insulator in Ir oxides
• Spin-Orbit Integrated Ground State and Magnetic Anisotropy in Sr${}_2$IrO${}_4$
• Multipole correlations of $t_{2g}$-orbital Hubbard model with spin-orbit coupling

Cited by in corpus (3)

• Theoretical study of insulating mechanism in multi-orbital Hubbard models with a large spin-orbit coupling: Slater versus Mott scenario in Sr${}_2$IrO${}_4$
• Spin-orbit-induced exotic insulators in a three-orbital Hubbard model with $(t_{2g}{)}^5$ electrons
• Spin-Orbital Entangled Excitonic Insulators in $(t_{2g}{)}^4$ Correlated Electron Systems