Subwavelength control of electromagnetic field confinement in self-similar chains of magnetoplasmonic core-shell nanostructures

We apply first-principles methodology to study the spatial localization of electric field enhancement at plasmonic resonance and magnetic field enhancement at gyroresonance in a self-similar chain of magnetoplasmonic core-shell nanostructures (MCSNs). Localized regions of high electric and magnetic fields in the vicinity of metal nanostructures can be created in a controlled manner by adjusting the physical parameters characterizing this system and the polarization of the external harmonic excitations. We demonstrate the high degree of control achieved on electric field confinement, of the order of 10(3), down to a feature size of λ/1000 in self-similar chains of MCSNs, where λ denotes the free space wavelength of the resonant excitation. We also compare our findings with recent investigations in related plasmonic nanostructures.