Dirac Fermions in Half-Metallic Ferromagnetic Mixed Cr_1-xM_xPSe₃ Monolayers

The electronic and magnetic properties of pristine CrPSe3 and mixed Cr1-xM(x)PSe(3) (M = Zn, Cd, Hg) monolayers are studied using density functional theory including an on-site Coulomb term (density functional theory (DFT) +U) and tight-binding approach. While pristine CrPSe3 monolayer has an antiferromagnetic ground state, its alloying with MPSe3 may give rise to half-metallic ferromagnet with high Curie temperature. The resulting monolayers demonstrate single-spin Dirac cones of mainly Cr-d character located in the first Brillouin zone directly at the Fermi energy. The calculated Fermi velocities of Dirac fermions indicate very high mobility in mixed Cr1-xM(x)PSe(3) monolayers, that makes this material appealing for low-dimensional spintronics applications.