Emergence of skyrmions from rich parent phases in the molybdenum nitrides

Abstract

We report a new family of skyrmion materials originated from the antisymmetric Dzyaloshinskii-Moriya (DM) interactions. Based on the symmetric tensor technique, the molybdenum nitrides with the \ensuremath{\beta}-manganese structure, ${A}_{2}\mathrm{M}{\mathrm{o}}_{3}\mathrm{N}$ with $A=\mathrm{Fe}$, Co, Rh, are predicted to support the skyrmion phase. This predication is directly proved in doped $\mathrm{F}{\mathrm{e}}_{x}\mathrm{C}{\mathrm{o}}_{1\ensuremath{-}x}\mathrm{R}{\mathrm{h}}_{0.5}\mathrm{M}{\mathrm{o}}_{3}\mathrm{N}$ components by high-resolution Lorentz transmission electron imaging. Interestingly, the parent compounds $\mathrm{F}{\mathrm{e}}_{2}\mathrm{M}{\mathrm{o}}_{3}\mathrm{N}, \mathrm{C}{\mathrm{o}}_{2}\mathrm{M}{\mathrm{o}}_{3}\mathrm{N}$, and $\mathrm{R}{\mathrm{h}}_{2}\mathrm{M}{\mathrm{o}}_{3}\mathrm{N}$ exhibit ferromagnetic, antiferromagnetic, and possible superconducting orderings, respectively. Magnetism in these parent phases is theoretically clarified by the first-principle calculations, where the corrected nature of the magnetism is revealed.