Electronic and magnetic properties of the RuX${}_3$ (X=Cl, Br, I) family: Two siblings -- and a cousin?

Abstract

Motivated by recent reports of metallic behavior in the recently synthesized RuI${}_3$, in contrast to the Mott-insulating nature of the actively discussed $\alpha$-RuCl${}_3$, as well as RuBr${}_3$, we present a detailed comparative analysis of the electronic and magnetic properties of this family of trihalides. Using a combination of first-principles calculations and effective-model considerations, we conclude that RuI${}_3$, similarly to the other two members, is most probably on the verge of a Mott insulator, but with much smaller magnetic moments and a strong magnetic frustration. We predict the ideal pristine crystal of RuI${}_3$ to have a nearly vanishing conventional nearest-neighbor Heisenberg interaction and to be a quantum spin liquid candidate of possibly different kind than the Kitaev spin liquid. In order to understand the apparent contradiction to the reported resistivity $\rho$, we analyze the experimental evidence for all three compounds and propose a scenario for the observed metallicity in existing samples of RuI${}_3$. Furthermore, for the Mott insulator RuBr${}_3$ we obtain a magnetic Hamiltonian of a similar form to that in the much discussed $\alpha$-RuCl${}_3$ and show that this Hamiltonian is in agreement with experimental evidence in RuBr${}_3$.

published manuscript version

References in corpus (20)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• $\alpha$-RuCl3: a Spin-Orbit Assisted Mott Insulator on a Honeycomb Lattice
• Models and Materials for Generalized Kitaev Magnetism
• Calculations of Hubbard U from first-principles
• 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
• Ferromagnetic Kitaev interaction and the origin of large magnetic anisotropy in $\alpha$-RuCl${}_3$
• Magnetic anisotropy in the Kitaev model systems Na2IrO3 and RuCl3
• Proximate ferromagnetic state in the Kitaev model material $\alpha$-RuCl${}_3$
• Sign structure of thermal Hall conductivity for in-plane-field polarized Kitaev magnets
• High-Field Quantum Disordered State in $\alpha$-RuCl3: Spin Flips, Bound States, and a Multi-Particle Continuum
• Magnetic Anisotropy in Spin-3/2 with Heavy Ligand in Honeycomb Mott Insulators: Application to CrI${}_3$
• Thermodynamic perspective on the field-induced behavior of $\alpha$-RuCl${}_3$
• Kitaev-like honeycomb magnets: Global phase behavior and emergent effective models
• Magnetism of Kitaev spin-liquid candidate material RuBr${}_3$
• Magnetoelastic coupling and effects of uniaxial strain in $\alpha$-RuCl${}_3$ from first principles
• Modified Curie-Weiss Law for $j_{\mathrm{eff}}$ Magnets
• Strongly electron-correlated semimetal RuI${}_3$ with a layered honeycomb structure
• High-field thermal transport properties of the Kitaev quantum magnet alpha-RuCl3: evidence for low-energy excitations beyond the critical field
• Effects of Disorder on the Pressure-Induced Mott Transition in $\kappa$-BEDT-TTF)${}_2$Cu[N(CN)${}_2$]Cl

Cited by in corpus (2)

• A $j_{\mathrm{eff}}=1/2$ Kitaev material on the triangular lattice: The case of NaRuO${}_2$
• Emergent orbital magnetization in Kitaev quantum magnets