Photoinduced topological phase transitions in Kitaev-Heisenberg honeycomb ferromagnets with the Dzyaloshinskii-Moriya interaction

We theoretically study topological properties of Floquet magnons in a laser-irradiated Kitaev-Heisenberg honeycomb ferromagnet with the Dzyaloshinskii-Moriya interaction by making use of the Floquet-Bloch theory. It is found that the Kitaev-Heisenberg honeycomb ferromagnet can reveal two topological phases with different Chern numbers when it is irradiated by the circular-polarized light. We find that the topological phase of the system can be switched from one topological phase to another one by adjusting the light intensity. The intrinsic Dzyaloshinskii-Moriya interaction plays a crucial role in the emergence of photoinduced topological phase transitions. It is shown that sign reversal of the thermal Hall conductivity is an important indicator on photoinduced topological phase transitions in the Kitaev-Heisenberg honeycomb ferromagnet.