Topologically insulating states in ternary transition metal dichalcogenides

Abstract

The topological and electronic properties of monolayered monoclinic transition metal dichalcogenide (TMD) alloys (1T′-M1−xNxX2 with M, N = Cr, Mo, W and X = S, Se) have been studied through calculations based on the projected Wannier functions obtained from first-principles calculations. We predict that the ternary compounds 1T′-Mo1−xCrxS2 with x up to 7/12 and all 1T′-Mo1−xWxSe2 host topologically insulating states with band gaps comparable to the pure systems. For Cr contained alloys, the mechanism of sign changing of Berry curvature is proposed to explain the trivial band topology of some configurations. The predicted topologically insulating ternary TMDs may be promising candidates for future realization of topological devices.