Two-Dimensional Valleytronics in Single-Layer t-ZrNY (Y = Cl, Br) Predicted from First Principles

Two-dimensional valleytronics, using the valley index of carriers to perform logic operations, serves as the basis of the next-generation information technologies. Here, using first-principles calculations and perturbation theory, we propose two promising two-dimensional valleytronic crystals in single-layer t-ZrNY (Y = Cl, Br). We demonstrate that the valley polarization in both systems can readily be achieved by magnetic doping, and in the conductive bands, it reaches as high as ∼83 meV. The underlying physics for valleytronic behaviors of these systems is revealed in detail. In addition, we suggest that the valley polarization can be modulated effectively by varying the magnetization direction. Our work provides exotic candidates to realize two-dimensional valleytronics.