Influence of electronic correlation on the valley and topological properties of VSiGeP monolayer.

Valley is used as a new degree of freedom for information encoding and storage. In this work, the valley and topological properties of the VSiGeP monolayer were studied by adjusting the value based on first-principles calculations. The VSiGeP monolayer remains in a ferromagnetic ground state regardless of the change in the value. The magnetic anisotropy of the VSiGeP monolayer is initially in-plane, and then turns out-of-plane with the increase in the value. Moreover, a topological phase transition is observed in the present VSiGeP monolayer with the increase in value from 0 to 3 eV, , the VSiGeP monolayer behaves as a bipolar magnetic semiconductor, a ferrovalley semiconductor, a half-valley metal characteristic, and a quantum anomalous Hall state. The mechanism of the topological phase transition behavior of the VSiGeP monolayer was analyzed. It was found that the variation in values would change the strength of the electronic correlation effect, resulting in the valley and topological properties. In addition, carrier doping was studied to design a valleytronic device using this VSiGeP monolayer. By doping 0.05 electrons per f.u., the VSiGeP monolayer with a value of 3 eV exhibits 100% spin polarization. This study indicates that the VSiGeP monolayer has potential applications in spintronic, valleytronic, and topological electronic nanodevices.