Wavelength‐Scale Spin Hall Shift of Light with Morphology‐Enhanced Scattering Efficiency from Nanoparticles.

Spin Hall (SH) shift of light from nanoparticles refers to the transverse displacement of scattered light due to spin–orbit interaction (SOI). Generally, the SH shift is small and suffers from inherent low scattering efficiency. In this paper, the SH shift and its corresponding scattering intensity are simultaneously enhanced for dual nanoparticles. Based on the generalized Lorentz‐Mie theory, the morphology of the nanoparticle is optimized to increase the scattering intensity while preserving the wavelength‐scale SH shift. The simultaneous enhancements are realized by manipulating the electric and magnetic dipolar modes to overlap at their resonances rather than the tails of the scattering. Meanwhile, a new pattern is identified on orbital momentum streamlines, revealing the near field's SOI. In addition, an experiment is proposed to detect the SH shifts in the far‐field observation plane. The scattering intensities from oblate spheroids are enhanced by one order of magnitude compared to the spherical counterparts. The findings may shed new light on the mechanism of light–matter interaction and facilitate the experimental detection of the SH effect of light. [ABSTRACT FROM AUTHOR]