Magnetic and topological properties in hydrogenated transition metal dichalcogenide monolayers

Abstract

Two-dimensional (2D) transition metal dichalcogenide (TMD) monolayers have currently been of immense interest in materials research because of their versatility, and tunable electronic and magnetic properties. In this study, we systematically studied the electronic and magnetic properties in pristine and hydrogenated 1T, 1T’, and 2H TMD monolayers. We found Group IV (Ti, Zr, and Hf), VI (Cr, Mo, and W), and X (Ni, Pd, and Pt) pristine TMD monolayers, respectively, mostly adopted 1T, 2H, and 1T as their stable structures, except for WTe2 which exhibits 1T’. The stable 1T’ structure only exists for pristine WTe2 and it had been identified as a topological insulator with a band gap of 0.11 eV. Upon hydrogenation, a structural phase transition occurred from 1T to 2H in Group IV, while for Group X, the stable structure remained 1T. For Group VI, the stable phase transitioned from 1T to 2H or 1T’ phases. Moreover, we found nineteen 2D magnetic materials through hydrogenation. Finally, further exploration of band topologies under hybrid functional calculations revealed that four of these identified magnetic monolayer structures exhibit quantum anomalous Hall effect. Our findings show that hydrogenated TMDs provide a new ground in searching for materials which have the potential for spintronics applications.