Kitaev spin-orbital bilayers and their moiré superlattices

Abstract

We determine the phase diagram of a bilayer, Kitaev spin-orbital model with inter-layer interactions (J), for several stackings and moiré superlattices. For AA stacking, a gapped Z2 quantum spin liquid phase emerges at a finite Jc. We show that this phase survives in the well-controlled large-J limit, where an isotropic honeycomb toric code emerges. For moiré superlattices, a finite-q inter-layer hybridization is stabilized. This connects inequivalent Dirac points, effectively 'untwisting' the system. Our study thus provides insight into the spin-liquid phases of bilayer spin-orbital Kitaev materials.

Emergent Hyper-Magic Manifold in Twisted Kitaev Bilayers

“…While our results for small values of J/K agree with Ref. [86], we successfully capture the effect of the varying stacking arrangement on the intralayer hopping, which was neglected in other works. We have shown that such terms allow one to isolate flat from dispersive bands.…”

“…While preparing this manuscript, we became aware of a related work [86]. While our results for small values of J/K agree with Ref.…”