Dimensionality Driven Spin-Flop Transition in Layered Iridates

Abstract

Using resonant x-ray diffraction, we observe an easy c-axis collinear antiferromagnetic structure for the bilayer Sr${}_3$Ir${}_2$O${}_7$, a significant contrast to the single layer Sr${}_2$IrO${}_4$ with in-plane canted moments. Based on a microscopic model Hamiltonian, we show that the observed spin-flop transition as a function of number of IrO${}_2$ layers is due to strong competition among intra- and inter-layer bond-directional pseudo-dipolar interactions of the spin-orbit entangled $J_{eff}$=1/2 moments. With this we unravel the origin of anisotropic exchange interactions in a Mott insulator in the strong spin-orbit coupling regime, which holds the key to the various types of unconventional magnetism proposed in 5$d$ transition metal oxides.

References in corpus (5)

• 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 $\infty$)
• Twisted Hubbard Model for Sr2IrO4: Magnetism and Possible High Temperature Superconductivity
• Long range magnetic ordering in Na${}_2$IrO${}_3$

Cited by in corpus (6)

• Giant Magnon Gap in Bilayer Iridate Sr3Ir2O7: Enhanced Pseudo-dipolar Interactions Near the Mott Transition
• Robustness of basal-plane antiferromagnetic order and the $J_{eff}=1/2$ state in single-layer iridate spin-orbit Mott insulators
• Testing the validity of the strong spin-orbit-coupling limit for octahedrally coordinated iridates in a model system Sr${}_3$CuIrO${}_6$
• Neutron scattering study of correlated phase behavior in Sr2IrO4
• Spin ordering and electronic texture in the bilayer iridate Sr${}_3$Ir${}_2$O${}_7$
• The J_{eff}=1/2 insulator Sr3Ir2O7 studied by means of angle-resolved photoemission spectroscopy