Spin splitting effect in strained g-wave altermagnets and in anisotropic ferromagnets

The spin splitting effect is the generation of a pure transverse spin current without the need for spin-orbit coupling, which is a promising application of altermagnets in spintronic devices. First, I will discuss strain-induced spin splitting effect in g-wave altermagnets. The strain-induced spin splitting effect in hole-doped MnTe semiconductor is predicted to have a giant gauge factor of more than 30, while it is usually of order 1 in metallic g-wave altermagnets. The giant effect in MnTe is associated with the lifting of the A-point degeneracy by the strain-induced crystal field. Next, I will show that the spin splitting effect is generically allowed in non-cubic ferromagnets thanks to the crystallographic anisotropy of the conductivity tensor. First-principles screening of 41 noncubic ferromagnets combined with the Boltzmann calculations in the relaxation-time approximation revealed that many of them, when grown as a single crystal with tilted crystallographic axes, can exhibit large spin splitting angles comparable with the best available spin-orbit-driven spin Hall sources.