Unified theory of spiral magnetism in the harmonic-honeycomb iridates α, β, γ Li2IrO3

Abstract

A family of insulating iridates with chemical formula Li${}_2$IrO${}_3$ has recently been discovered, featuring three distinct crystal structures $\alpha ,\beta ,\gamma$ (honeycomb, hyperhoneycomb, stripyhoneycomb). Measurements on the three-dimensional polytypes, $\beta$- and $\gamma$-Li${}_2$IrO${}_3$, found that they magnetically order into remarkably similar spiral phases, exhibiting a non-coplanar counter-rotating spiral magnetic order with equivalent q=0.57 wavevectors. We examine magnetic Hamiltonians for this family and show that the same triplet of nearest-neighbor Kitaev-Heisenberg-Ising (KJI) interactions reproduces this spiral order on both $\beta ,\gamma$-Li${}_2$IrO${}_3$ structures. We analyze the origin of this phenomenon by studying the model on a 1D zigzag chain, a structural unit common to the three polytypes. The zigzag-chain solution transparently shows how the Kitaev interaction stabilizes the counter-rotating spiral, which is shown to persist on restoring the inter-chain coupling. Our minimal model makes a concrete prediction for the magnetic order in $\alpha$-Li${}_2$IrO${}_3$.

v2: minor revisions for clarity, v3: published version. 9 pages, 5 figures

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Cited by in corpus (24)

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• Hidden symmetries of the extended Kitaev-Heisenberg model: Implications for honeycomb lattice iridates A2IrO3
• Raman spectroscopic signature of fractionalized excitations in the harmonic-honeycomb iridates $\beta$- and $\gamma$-Li${}_2$IrO${}_3$
• Physical states and finite-size effects in Kitaev's honeycomb model: Bond disorder, spin excitations, and NMR lineshape
• Dominant Kitaev interactions in the honeycomb materials Na${}_3$Co${}_2$SbO${}_6$ and Na${}_2$Co${}_2$TeO${}_6$
• Magnon damping in the zigzag phase of the Kitaev-Heisenberg-$\Gamma$ model on a honeycomb lattice
• Revealing frustrated local moment model for pressurized hyperhoneycomb iridate: paving a way toward quantum spin liquid
• Kitaev magnetism through the prism of lithium iridate
• Spin interaction and magnetism in cobaltate Kitaev candidate materials: an $ab$ $initio$ and model Hamiltonian approach
• Field stability of Majorana spin liquids in antiferromagnetic Kitaev models
• The Saga of $\alpha$-RuCl${}_3$: Parameters, Models, and Phase Diagrams
• Resonant inelastic x-ray scattering spectra in the hyperhoneycomb iridate $\beta$-Li${}_2$IrO${}_3$: First principles calculations
• Electronic excitations in $\gamma$-Li${}_2$IrO${}_3$
• Magnetic Excitations and Interactions in the Kitaev Hyperhoneycomb Iridate $\beta$-Li${}_2$IrO${}_3$
• Thermal conductivity of local moment models with strong spin-orbit coupling
• Optical magnons with dominant bond-directional exchange interactions in a honeycomb lattice iridate $\alpha$-Li${}_2$IrO${}_3$
• Lattice dynamics and structural transition of the hyperhoneycomb iridate $\beta$-Li${}_2$IrO${}_3$ investigated by high-pressure Raman scattering
• Ground-State Phase Diagram of the Kitaev-Heisenberg Model on a Three-dimensional Hyperhoneycomb Lattice
• Bound states of fractionalized excitations in a modulated Kitaev spin liquid
• From chiral d-wave to nodal line superconductivity in the harmonic honeycomb lattices
• Non-local features of the spin-orbit exciton in Kitaev materials
• Minimal models of $\alpha$-Li${}_2$IrO${}_3$: On the range of the interactions, ground state properties, and magnetization processes
• The nature of low-temperature spin-freezing in frustrated Kitaev magnets
• Topological quantum phase transitions of anisotropic AFM Kitaev model driven by magnetic field