In-Plane Quantum Anomalous Hall Effect in Ferromagnetic Type-I Nodal Line Semimetal of Monolayer YbN

The monolayer YbN is predicted to be a 2D nodal line semimetal with full spin polarization in the absence of spin-orbit coupling as well as an intrinsic ferromagnet with an easy magnetic xy plane and T-c = 85 K. Considering the spin-orbit coupling with magnetic moments along z direction, the band crossings near Fermi level around Gamma points are still preserved and robust against spin-orbit coupling. On the contrary, when the spin-orbit coupling is considered with magnetic moments oriented in-plane along x and y directions, the band crossings are broken, and the bandgap of the magnetic moment along the y direction is larger than that in the x direction, which results in topologically nontrivial insulating property. The anomalous Hall conductivity calculations show the Chern number C = -1, implying the existence of one edge state in the finite-width nanoribbon. The findings provide ideal candidates for investigating the design of electronic devices related to 2D nontrivial magnetic materials.