Revealing Electric‐Magnetic Asymmetry of Transverse Spin Angular Momentum using Polarization‐Selected Chiral Lateral Forces

ABSTRACT Lateral optical forces induced by transverse spin angular momentum (SAM) have been proposed to sort chiral dipole particles. In practice, the magnetic dipole response of common nonmagnetic materials is weak, which obscures the respective roles of the electric and magnetic components of transverse SAM in the forces exerted on chiral particles. Here, this study proposes a strategy for cleanly separating the lateral forces driven by electric and magnetic transverse SAM by precise polarization control of multiple linearly polarized plane waves. This approach enables the selective generation of electric or magnetic dominant transverse SAM and allows manipulation of chirality‐dependent forces on isotropic chiral particles across sizes from the Rayleigh to the Mie regime. Furthermore, for two wave and three wave configurations, a quantitative relationship is established among the lateral force, particle chirality, multipolar contributions, and the electric or magnetic transverse SAM. The analysis explains force reversals that occur when switching the dominant transverse SAM component in the excitation field and attributes the observed imbalance to electromagnetic symmetry breaking of the scatterer. The results deepen the understanding of spin–mediated light–matter interactions and broaden opportunities for chiral sensing and sorting.