$J=1/2$ Pseudospins and $d$-$p$ Hybridization in the Kitaev Spin Liquid Candidates Ru$X_3$ ($X$ = Cl, Br, I)

Abstract

The recent synthesis of ruthenium trihalides Ru$X_3$ ($X$ = Cl, Br, I) has enlarged the set of material candidates for Kitaev spin liquid. The realization of Kitaev model necessitates the formation of $J=1/2$ pseudospins in the octahedral crystal field. We use Ru $L_3$-edge resonant inelastic x-ray scattering to investigate the evolution of multiplet structures in Ru$X_3$. We identified quasi-elastic magnetic correlations and spin-orbit transitions to the $J=3/2$ states without discernible trigonal splitting, thereby validating the $J=1/2$ description of magnetism in the Ru$X_3$ family. Lineshape broadening in RuI${}_3$ provides evidence for its bulk metallicity in the vicinity of a bandwidth-controlled metal-insulator transition. Our results highlight the pivotal role of halogen $p$ orbitals in controlling the electronic properties of Ru$X_3$.

References in corpus (17)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Strong electronic correlations from Hund's coupling
• Scattering Continuum and Possible Fractionalized Excitations in $\alpha$-RuCl${}_3$
• Magnetic order in $\alpha$-RuCl${}_3$: a honeycomb lattice quantum magnet with strong spin-orbit coupling
• Successive magnetic phase transitions in $\mathbf{\alpha }$-RuCl${}_3$: XY-like frustrated magnet on the honeycomb lattice
• Pseudospin exchange interactions in d^7 cobalt compounds: Possible realization of the Kitaev model
• Crystal field splitting and correlation effect on the electronic structure of A2IrO3
• Kitaev-Heisenberg Hamiltonian for High-Spin $d^7$ Mott Insulators
• Microscopic mechanism for higher-spin Kitaev model
• Proximate ferromagnetic state in the Kitaev model material $\alpha$-RuCl${}_3$
• Magnetic Anisotropy in Spin-3/2 with Heavy Ligand in Honeycomb Mott Insulators: Application to CrI${}_3$
• Kitaev materials beyond iridates: order by quantum disorder and Weyl magnons in rare-earth double perovskites
• Magnetism of Kitaev spin-liquid candidate material RuBr${}_3$
• Magnetoelastic coupling and effects of uniaxial strain in $\alpha$-RuCl${}_3$ from first principles
• Strongly electron-correlated semimetal RuI${}_3$ with a layered honeycomb structure
• Contrasting electronic states of RuI3 and RuCl3
• Resonant Inelastic X-ray Scattering from Electronic Excitations in $\alpha$-RuCl${}_3$ Nanolayers

Cited by in corpus (3)

• Anisotropic magnetic interactions in a candidate Kitaev spin liquid close to a metal-insulator transition
• Evolution of crystal field and intraionic interactions in the ilmenite $A$IrO${}_3$ ($A$ = Mg, Zn, Cd) and hyperhoneycomb $\beta$-ZnIrO${}_3$
• Low-temperature spin dynamics and absence of magnetic order in layered $\alpha$-RuI${}_3$