Ground-state phase diagram of the Kitaev-Γ model on a honeycomb lattice

We investigate the ground-state phase diagram of the Kitaev-Γ model on a honeycomb lattice by utilizing series expansions and numerical exact diagonalizations [1]. We focus on the effects of the anisotropic interactions. Starting from the weakly interacting dimers on the specific bond, we strengthen the interdimer interactions up to the isotropically interacting system. Depending on the strengths of the Kitaev and Γ interactions, the dimer state survives up to the isotropically interacting system, where the phase transition occurs, or obeys a phase transition to a magnetically ordered state at an anisotropic interaction. The results are summarized in the phase diagrams. We also show that the Kekulé dimerized state is unstable in the isotropic Kitaev-Γ model. [1] T. Yamada, T. Suzuki, and S. Suga, PRB 102, 024415 (2020).