NaRuO${}_2$: Kitaev-Heisenberg exchange in triangular-lattice setting

Abstract

Kitaev exchange, a new paradigm in quantum magnetism research, occurs for 90${}^{\circ }$ metal-ligand-metal links, $t_{2g}^5$ transition ions, and sizable spin-orbit coupling. It is being studied in honeycomb compounds but also on triangular lattices. While for the former it is known by now that the Kitaev intersite couplings are ferromagnetic, for the latter the situation is unclear. Here we pin down the exchange mechanisms and determine the effective coupling constants in the $t_{2g}^5$ triangular-lattice material NaRuO${}_2$, recently found to host a quantum spin liquid ground state. We show that, compared to honeycomb compounds, the characteristic triangular-lattice cation surroundings dramatically affect exchange paths and effective coupling parameters, changing the Kitaev interactions to antiferromagnetic. The quantum chemical analysis and subsequent effective spin model computations provide perspective onto the nature of the experimentally observed quantum spin liquid -- it seemingly implies finite longer-range exchange, and the atypical proximity to ferromagnetic order is related to sizable ferromagnetic Heisenberg nearest-neighbor couplings.

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• Spin liquid phase of the $S=\frac{1}{2}$ $J_1-J_2$ Heisenberg model on the triangular lattice
• Magnetization processes of zigzag states on the honeycomb lattice: Identifying spin models for $\alpha$-RuCl${}_3$ and Na${}_2$IrO${}_3$
• Magnetic state of pyrochlore Cd2Os2O7 emerging from strong competition of ligand distortions and longer-range crystalline anisotropy
• Identification of Magnetic Interactions and High-field Quantum Spin Liquid in $\alpha$-RuCl${}_3$
• Extraction of the interaction parameters for $\alpha -$RuCl${}_3$ from neutron data using machine learning
• A $j_{\mathrm{eff}}=1/2$ Kitaev material on the triangular lattice: The case of NaRuO${}_2$
• Defect control in the Heisenberg-Kitaev candidate material NaRuO${}_2$
• Thermal Properties and Instability of a $U(1)$ Spin Liquid on the Triangular Lattice

Cited by in corpus (11)

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• Dominant Kitaev interaction and field-induced quantum phase transitions in triangular-lattice KCeSe2
• Sweet spot in the RuCl${}_3$ magnetic system: nearly ideal $j_{\mathrm{eff}}=1/2$ moments and maximized $K/J$ ratio under pressure
• Searching for superconductivity in doped triangular lattice Kitaev magnets
• Quantum selection of order and dynamic properties of Kitaev-Heisenberg ferromagnet on a triangular lattice
• (H,Li)${}_6$Ru${}_2$O${}_6$ : a possible zero-field Ru${}^{3+}$-based Kitaev Quantum Spin Liquid
• Ferrichiral skyrmions with sublattice-resolved chirality in extended Kitaev model in triangular lattice
• Relevance of on-site and intersite Coulomb interactions in the Kitaev-Heisenberg magnet Na${}_3$Co${}_2$SbO${}_6$
• Spin-orbit driven $J_{eff}=1/2$ magnetism in a d${}^7$ triangular-lattice monolayer cobaltate
• More bridging ligands activate direct exchange: the case of anisotropic Kitaev effective magnetic interactions
• Impurity-induced moment freezing in NaFe${}_x$Ru${}_{1-x}$O${}_2$