Hybridization and manipulation of Mie resonances in a single symmetry-breaking Si nanosphere

Breaking the geometrical symmetry of metallic nanostructures can give rise to a variety of intriguing optical phenomena, with significant implications for biosensors, nanoantennas, metamaterials, and optical switches. However, the practical application of these phenomena in the visible spectrum is hindered by the inherent ohmic losses associated with metallic materials. In this work, we propose a theoretically designed single dielectric silicon nanosphere with broken symmetry, achieved by introducing a cavity along its symmetry axis. Inspired by the theory of plasmon hybridization, we demonstrate the emergence of bonding and anti-bonding dipole-dipole coupling modes resulting from the interaction between the nanosphere and the cavity. By performing multipole expansion analysis of electromagnetic scattering, we clarify the distinct contributions of electric and magnetic dipoles to these coupling modes. Moreover, these modes can be effectively tuned by adjusting the geometric parameters of both the nanosphere and the cavity. This study enhances the understanding of light-matter interactions in symmetry-breaking dielectric nanostructures and provides a foundation for the development of advanced dielectric-based devices for applications in optical communications, biosensing, and quantum technologies.