Magnetic and Electronic Evolutions of Hydrogenated VTe2 Monolayer under Tension

Two-dimensional nanostructures with controllable magnetic and electronic properties are desirable for their versatile applications in quantum devices. Here, we present a first-principles design on their magnetic and electronic switching controlled by tension. We find that hydrogenated VTe2 monolayer experiences a transfer from anti-ferromagnetism to ferromagnetism via a turning-point of paramagnetism, and switches from semiconductor, to metal, further to half-metal as tension increases. We show that its anti-ferromagnetism with semiconducting or metallic character under low tension is contributed to super-exchange or mobile-carrier enhanced super-exchange, while the ferromagnetism with half-metallic character under high tension is induced by carrier-mediated double exchange. We further show that the magnetic and electronic evolutions of hydrogenated VS2 and VSe2 monolayers under tension follow the same trend as those of hydrogenated VTe2 monolayer. We predict that tension is efficient and simple to control the magnetic and electronic properties of hydrogenated vanadium dichalcogenides monolayers. The monolayers with controllable magnetism and conductivity may find applications in multi-functional nanodevices.