Floquet Theory of Photoinduced Topological Phase Transitions in the Organic Salt Α-(Bedt-ttf)2i3 Irradiated with Elliptically Polarized Light

We theoretically investigate possible photoinduced topological phase transitions in the organic salt α-(BEDT-TTF)2I3, which possesses a pair of inclined massless Dirac-cone bands between the conduction and valence bands under uniaxial pressure. The Floquet analyses of a driven tight-binding model for this material reveal rich photoinduced variations of band structures, Chern numbers, and Hall conductivities under irradiation with elliptically polarized light. The obtained phase diagrams contain a variety of nonequilibrium steady phases, e.g., the Floquet Chern insulator, Floquet semimetal, and Floquet normal insulator phases. This work widens a scope of target materials for research on photoinduced topological phase transitions and contributes to development of research on the optical manipulations of electronic states in matters.