Superlattice material, and preparation method and application thereof

A superlattice material, comprising a substrate and a superlattice structure disposed on the substrate, wherein

• the superlattice structure is [first ferrimagnetic thin film/two-dimensional material layer/second ferrimagnetic thin film]n, and n≥1;
• the first ferrimagnetic thin film, the two-dimensional material layer, and the second ferrimagnetic thin film are laminated successively;
• a material of the two-dimensional material layer is one or more of graphene, an insulator, a transition metal chalcogenide, and black phosphorus;
• the first ferrimagnetic thin film and the two-dimensional material layer form a heterojunction structure, and the two-dimensional material layer and the second ferrimagnetic thin film form a heterojunction structure:
• the insulator is one or more of Bi2Te3, Bi2Se3, and Bi0.9Te0.1;
• a material of the first ferrimagnetic thin film and the second ferrimagnetic thin film is independently garnet type ferrites;
• and the garnet type ferrite is one or more of yttrium iron garnet, thulium iron garnet, and lutetium bismuth iron garnet;
• a thicknesses of the first ferrimagnetic thin film and the second ferrimagnetic thin film are independently 1 nm to 10 μm;
• a magneto-optical Kerr angle of the superlattice material is increased by 2.5 times compared with ferrimagnetic thin film material in which nor two-dimensional material is inserted.