Intercalated Kitaev magnets in the clean and disordered limits

In recent years, a new class of intercalated Kitaev materials has emerged from the substitution of interlayer Li and Na atoms in Li₂IrO₃ and Na₂IrO₃ with Cu, Ag, and H. Examples of such materials include Cu₂IrO₃, Cu₃LiIr₂O₆, Ag₃LiIr₂O₆, and H₃LiIr₂O₆. Some of the early studies on these materials have shown promising evidence of proximity to a Kitaev spin liquid grounds state with anyonic excitations. For example, the lack of magnetic ordering, a scaling behavior of the specific heat, and a two-step release of magnetic entropy are all consistent with the theoretical prediction of a spin liquid ground state with fractionalized excitations. Here we present a careful overview of the properties of these materials and compare their magnetic behaviors in the clean and disordered limits. Specifically, we scrutinize the role of interlayer coupling in the physics of Kitaev magnets and demonstrate how the stacking faults and bond randomness can impair our understanding of the magnetism in the clean limit. We also show that unlike some of the early reports, magnetic ordering is not always suppressed after Cu or Ag exchange. In fact, the magnetism can be fortified by intercalation in the limit of weak spin-orbit coupling. This presentation will give an honest overview of the recent candidate materials for the Kitaev spin liquid phase and clarifies some of the controversial findings in the field.