Three-Dimensional Giant Invisibility to Superscattering Enhancement Induced by Zeeman-Split Modes

We report that the fundamental three-dimensional (3-D) scattering single-channel limit can be exceeded in magneto-optical assisted systems by inducing nondegenerate magnetoplasmonic modes. In addition, we propose a 3-D active (magnetically assisted) forward-superscattering to invisibility switch, functioning at the same operational wavelength. Our structure is composed of a high-index dielectric core coated by indium antimonide (InSb), a semiconductor whose permittivity tensorial elements may be actively manipulated by an external magnetic bias B 0 . In the absence of B 0, InSb exhibits isotropic epsilon-near-zero (ENZ) and plasmonic behavior above and below its plasma frequency, respectively, a frequency band which can be utilized for attaining invisibility using cloaks with permittivity less than that of free space. With realistic B 0 magnitudes as high as 0.17 T, the gyroelectric properties of InSb enable the lift of mode degeneracy, and the induction of Zeeman-split type magnetoplasmonic modes that beat the fundamental single-channel limit. Moreover, we show that chains of such particles, where each one operates in its superscattering regime, enable giant off-to-on enhancement in scattering efficiency, as well as unprecedentedly high forward scattering. These all-in-one designs allow for the implementation of functional and readily tunable optical devices.