Hidden spin-orbital order in the Kitaev hyperhoneycomb $\beta$-Li${}_2$IrO${}_3$

Abstract

We report the existence of a phase transition at high temperature in the 3D Kitaev candidate material, $\beta$-Li${}_2$IrO${}_3$. We show that the transition is bulk, intrinsic and orders a tiny magnetic moment with a spatially anisotropic saturation moment. We show that even though this transition is global, it does not freeze the local Ir moments, which order at much lower temperatures into an incommensurate state. Rather, the ordered moment has an orbital origin that is coupled to spin correlations, likely of a Kitaev origin. The separate ordering of spin-correlated orbital moments and of local Ir moments reveals a novel way in which magnetic frustration in Kitaev systems can lead to coexisting magnetic states.

arXiv comment7 pages, 5 Figures

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Cited by in corpus (10)

• Beyond Kitaev physics in strong spin-orbit coupled magnets
• Kitaev magnetism through the prism of lithium iridate
• Magnon-spinon dichotomy in the Kitaev hyperhoneycomb $\beta$-Li${}_2$IrO${}_3$
• Reentrant incommensurate order and anomalous magnetic torque in the Kitaev magnet $\beta$-${\text{Li}}_2{\text{IrO}}_3$
• Interplay of magnetism and dimerization in pressurized Kitaev material $\beta$-Li${}_2$IrO${}_3$
• Signatures of non-Loudon-Fleury Raman scattering in the Kitaev magnet $\beta$-Li${}_2$IrO${}_3$
• High-temperature magnetic anomaly via suppression of antisite disorder through synthesis route modification in a Kitaev candidate Cu${}_2$IrO${}_3$
• Signatures of fractionalization in the optical phonons of hyperhoneycomb Kitaev magnet $\beta$-Li${}_2$IrO${}_3$
• Collapse of susceptibility and non-trivial spin dynamics in the hyper-honeycomb magnet $\beta$-Li${}_2$IrO${}_3$ under high pressure
• Non-Loudon-Fleury Raman scattering in spin-orbit coupled Mott insulators