Magnetoplasmon excitation and hybridization in gyroelectric cylinders

We investigate magnetoplasmon resonances and their coupling effects in gyroelectric cylinders. In individual cylinders, the dipole plasmon can be excited by plane wave illumination, and the dipole plasmon splits into lower energy and higher energy rotational magnetoplasmons in the presence of an external magnetic field. With respect to the external magnetic field, the two magnetoplasmons carry either right-handed chirality or left-handed chirality. In addition, originally dark plasmons can also be excited as the magnetic field increases. They are lower-order bulk plasmons (such as the radial breathing mode). In cylindrical dimers, the optically bright modes are combinations of magnetoplasmons with the same chirality. If the magnetic fields are antiparallel, the absorption spectra will be different for light incident from two opposite directions. This asymmetry can be well understood by carrying out eigenstate analysis, where the eigenstate does not possess mirror symmetry respecting the dimer axis. The dark modes engineering and asymmetrical optical behavior could have potential for terahertz device applications.