Strain effects in α-RuCl₃ from first principles

In recent years, the ‘proximate’ Kitaev spin liquid candidate, α-RuCl₃, is under active study for exploring ways to tune it out of the zigzag antiferromagnetic order. Hence, different routes to enhance magnetic Kitaev interaction in α-RuCl₃ are pursued. First, we studied the effects of uniaxial strain in bulk α-RuCl₃, when applied perpendicular to the honeymoon plane. In particular, we have explored the magnetoelastic coupling in α-RuCl₃ and the dependence of magnetic coupling constants on strain effects. We find that Kitaev interaction gets strongly enhanced under compression. Secondly, we have explored another route of straining α-RuCl₃: by a substrate, graphene (gr). Due to proximity effect and charge transfer, α-RuCl₃ in the heterostructure system becomes lightly electron-doped, exhibiting insulator to metal transition. Quantum oscillation measurements of α-RuCl₃/gr system show anomalous temperature dependence and we will discuss how to extract ab initio parameters for Kitaev-Kondo lattice modelling which can explain such anomaly.