Light-induced Odd-parity Magnetism in Conventional Collinear Antiferromagnets

Recent studies have drawn growing attention on non-relativistic odd-parity magnetism in the wake of altermagnets. Nevertheless, odd-parity spin splitting is often believed to appear in non-collinear magnetic configurations. Here, using symmetry arguments and effective model analysis, we show that Floquet engineering offers a universal strategy for achieving odd-parity magnetism in two-dimensional (2D) collinear antiferromagnets under irradiation of periodic driving light fields such as circularly polarized light, elliptically polarized light, and bicircular light. A comprehensive classification of potential candidates for collinear monolayer or bilayer antiferromagnets is established. Strikingly, the light-induced odd-parity spin splitting can be flexibly controlled by adjusting the crystalline symmetry or the polarization state of incident light, enabling the reversal or conversion of spin-splitting. By combining first-principles calculations and Floquet theorem, we present illustrative examples of 2D collinear antiferromagnetic (AFM) materials to verify the light-induced odd-parity magnetism. Our work not only offers a powerful approach for uniquely achieving odd-parity spin-splitting with high tunability, but also expands the potential of Floquet engineering in designing unconventional compensated magnetism.