Enhanced broadband spin Hall effects by core-shell nanoparticles

• Main Authors: Shi, R., Wang, Y. Q., Gao, L., Gao, Dong Liang, Hu, Hao
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2019
• Subjects: Metamaterials; Engineering::Electrical and electronic engineering; Nanophotonics
• Online Access: https://hdl.handle.net/10356/106323; http://hdl.handle.net/10220/49621; http://dx.doi.org/10.1364/OE.27.004808
• Institution: Nanyang Technological University

Spin-orbit interaction of light is ubiquitous in any optical system. However, the relevant spin Hall effects are usually weak for the light scattering from nanoparticles, making it challengeable to detect directly in experiment. In this paper, we demonstrate enhanced broadband spin Hall effects by using core-shell nanoparticles. The electric and magnetic dipoles can be tuned by the core-shell nanostructure with great freedom, and are excited simultaneously in a broadband spectrum, resulting in robust enhanced spin Hall shifts. Moreover, the coupling of the electric dipole and electric quadrupole gives rise to enhanced spin Hall shifts at both forward and backward directions. Numerical results from far-field and near-field verify the strong spin-orbit interaction of light. Our work offers a new way to exploit spin Hall effects in superresolution imaging and spin-dependent displacement sensing.