Design of a polar half-metallic ferromagnet with accessible and enhanced electric polarization

We design a compound belonging to a class of materials designated as polar half-metallic ferromagnets, where a 100% spin polarization coexists with polar distortions that globally lift inversion symmetry. Using electronic structure calculations, we predict that the ultrashort period (LaNiO3)1/(YCrO3)1 superlattice belongs to this materials class, exhibiting an integer magnetic moment of 4?B. The minority channel electric polarization, as computed using Berry phase theory, is as high as ~13.0?Ccm-2, and we discuss experimental strategies to access the polarization. We propose that polar ferromagnetic half-metals exhibit multiferroism and can be exploited to realize nonreciprocal effects and directional anisotropy owing to the absence of both space-inversion and time-reversal symmetries.