Theoretical prediction of physics characteristics for monolayer GdITeH

Abstract

In this study, we predict a new two-dimensional (2D) ferromagnet, GdITeH, using first-principles calculations. Monolayer GdITeH is a bipolar magnetic semiconductor, which exhibits robust kinetics and thermal stability, possesses a high Curie temperature of 314 K, and displays a strong magnetic anisotropy of 1.05 meV. The magnetic anisotropy throughout the space exhibits a strong dependence on the polar angle, whereas it is isotropic within the xOy plane. Due to broken inversion and time-reversal symmetries, magnetization along the z-axis induces valley polarization and valley contrast characteristics, which can be tuned by an external magnetic field. The valley splitting is as high as 195.6 meV, and the Berry curvature at K and K′ points is 20.3 and −14.6 Å2, respectively, as the magnetization direction aligns with the +z axis. The ferromagnetism and bipolar magnetic semiconductor nature of GdITeH remain stable under biaxial strain ranging from −2% to +2%. Charge doping can facilitate the transition of the system from a bipolar magnetic semiconductor to a single-spin channeled metal. Furthermore, bilayer GdITeH is sensitive to the stacking order, which can be tuned between ferromagnetic and antiferromagnetic configurations via lateral shifting. The AA-1 and AA-2 stacked structures exhibit significant valley contrast when magnetized along the z-axis, with valley splitting energy and Berry curvature as high as 196.7 meV and 42.2 Å2, respectively. These results indicate that monolayer GdITeH is a promising material for 2D spintronic applications and spin-valley electronics applications.