  Magnetism-driven nonrelativistic spin splittings (NRSS) are promising for
highly efficient spintronics applications. Although 2D centrosymmetric (in
four-dimensional spacetime) antiferromagnets are abundant, they have not
received extensive research attention owing to symmetry-forbidden spin
polarization and magnetization. Here, we demonstrate a paradigm to harness NRSS
by twisting the bilayer of centrosymmetric antiferromagnets with commensurate
twist angles. We observe $i$-wave altermagnetism and spin-momentum locking by
first-principles simulations and symmetry analysis on prototypical MnPSe$_3$
and MnSe antiferromagnets. The strength of NRSS (up to 80 meV\AA) induced by
twisting is comparable to SOC-induced linear Rashba-Dresselhaus effects. The
results also demonstrate how applying biaxial strain and a vertical electric
field tune the NRSS. The findings reveal the untapped potential of
centrosymmetric antiferromagnets and thus expand the material's horizons in
spintronics.
