Light-induced nonlinear Edelstein effect under ferroaxial ordering
Phys. Rev. B 113, 205108 – Published 4 May, 2026
DOI: https://doi.org/10.1103/m4k3-mttk
Abstract
Ferroaxial ordering, a spontaneous rotational distortion of the atomic arrangement, brings about a cross-product-type spin-orbit coupling (SOC) manifested as an electric toroidal (ET) dipole. We propose the light-induced nonlinear Edelstein effect (NLEE)—a second-order optical response in which a static magnetization is induced by a time-dependent electric field—as a promising probe of ferroaxial ordering. First, we elucidate the relationship between the NLEE tensor and the ET dipole. By decomposing the polarization modes of light, we find that both the linearly and circularly polarized light couple to the ET dipole via distinct mechanisms. We then demonstrate the NLEE using a minimal model that incorporates ferroaxial ordering. Our analysis reveals that effective coupling between orbital magnetization and SOC induces spin magnetization. The spin magnetization is tilted owing to the ET dipole; the tilt angle reflects the ratio between the ferroaxial-origin SOC and the relativistic SOC.
