Identification of Topological Phase Transitions in Kitaev Quantum Spin Liquids

We investigate physical quantities of a spin model and argue that magnetic field angle dependence and resonant inelastic X-ray scattering may probe topological phase transitions in Kitaev quantum spin liquids (KQSLs). By using exact-diagonalization, spin-wave theory, and parton mean field analysis, characteristic signatures of topological phase transitions in KQSLs are obtained in a spin model with the Kitaev, Heisenberg, and off-diagonal symmetric terms. Especially, we find qualitative differences between KQSLs and zig-zag ordered phases. We also apply our results to a candidate system α-RuCl3 and provide smoking-gun experiments.