Color symmetry and altermagneticlike spin textures in noncollinear antiferromagnets

We present a formalism based on color symmetry to analyze the momentum-space spin textures of noncollinear antiferromagnets. We show that, out of the spin textures allowed by the magnetic point group, one can extract a component that is invariant by general rotations in spin space, and can exist in the absence of spin-orbit coupling, in complete analogy to spin textures in altermagnets. We demonstrate this approach in the case of three complex, noncollinear magnets, {Mn}₃Ir(Ge,Si) , {Pb}₂{MnO}₄ , and {Mn}₃GaN . For {Mn}₃GaN , we also show that the predictions of color-symmetry analysis are consistent with density functional theory calculations performed on the same system both with and without spin-orbit coupling.