We predict a new class of two-dimensional (2D) materials, termed dual-switchable ferroelectric altermagnets (FEAMs), where reversing the ferroelectric polarization simultaneously alters both electronic spin splitting and magnonic chirality splitting. This provides a pathway for the unified electrical manipulation of both ground-state electron spin textures and collective magnon excitations within a single monolayer, a largely unexplored area. Employing symmetry analysis and first-principles calculations on five candidates identified via database screening (exemplified by CrPS3 and V2I2O2BrCl), we elucidate the mechanism in FEAMs. Ferroelectricity driven by specific atomic displacements breaks inversion symmetry while preserving key spin group symmetries (e.g., C2||M). This dual switch could be experimentally observed through a magneto-optical Kerr effect sign change. This work establishes a material-specific pathway toward integrating electrical control over coupled electronic and magnonic properties in two dimensions, paving the way for novel multifunctional spintronic and magnonic applications.
Wang et al. (Tue,) studied this question.