Tunable magneto-optical effect, anomalous Hall effect and anomalous Nernst effect in two-dimensional room-temperature ferromagnet 1T-CrTe2
Abstract
Utilizing the first-principles density functional theory calculations together with group theory analyses, we systematically investigate the spin order-dependent magneto-optical effect (MOE), anomalous Hall effect (AHE), and anomalous Nernst effect (ANE) in a recently discovered two-dimensional room-temperature ferromagnet 1T-CrTe2. We find that the spin prefers an in-plane direction by the magnetocrystalline anisotropy energy calculations. The MOE, AHE, and ANE display a period of 2π/3 when the spin rotates within the atomic plane, and they are forbidden if there exists a mirror plane perpendicular to the spin direction. By reorienting the spin from in-plane to out-of-plane direction, the MOE, AHE, and ANE are enhanced by around one order of magnitude. Moreover, we establish the layer-dependent magnetic properties for multilayer 1T-CrTe2 and predict antiferromagnetism and ferromagnetism for bilayer and trilayer 1T-CrTe2, respectively. The MOE, AHE, and ANE are prohibited in antiferromagnetic bilayer 1T-CrTe2 due to the existence of the spacetime inversion symmetry, whereas all of them are activated in ferromagnetic trilayer 1T-CrTe2 and the MOE is significantly enhanced compared to monolayer 1T-CrTe2. Our results show that the magneto-optical and anomalous transports proprieties of 1T-CrTe2 can be effectively modulated by altering spin direction and layer number.