Light-Induced Odd-Parity Magnetism in Conventional Antiferromagnetism

Recent studies have drawn growing attention on nonrelativistic odd-parity magnetism in the wake of altermagnets. Nevertheless, odd-parity spin splitting is often believed to appear in noncollinear 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 antiferromagnetism under irradiation of periodic driving light fields such as circularly polarized light, elliptically polarized light, and bicircular light. The symmetry requirements and three distinct lattice models of potential candidates are 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 Letter 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.