B5N5 Monolayer: A Room-temperature Light Element Antiferromagnetic Insulator
We demonstrate theoretically the intrinsic antiferromagnetic phase exists in monolayer materials consisting of non-magnetic light atoms, and propose B5N5 with decorated bounce lattice, is a thermal dynamically stable two-dimensional antiferromagnetic insulator, by performing the state-of-the-art density functional calculations. The antiferromagnetic phase originates from spontaneous symmetry breaking at the nearly flat bands in vicinity of the Fermi energy. The flat bands are formed by purely s-pz orbitals and are spin degenerate. Perpendicular electric field can remove the spin degeneracy and a prototype controllable dual spin filter with 100% spin polarization is proposed. Our proposal offers a possible two-dimensional atomically thick antiferromagnet insulator.