Symmetry-guided Design Principles for Spin Splitting and Hall Transport in Orthorhombic Altermagnetic Perovskites

Magnetic symmetry can generate momentum-dependent spin-split electronic bands even in the absence of spin-orbit coupling (SOC), giving rise to the recently discovered class of altermagnets. Here, we establish a unified symmetry framework for collinear antiferromagnets in orthorhombic Pbnm perovskite