Tunable magneto-optical Faraday rotation with a five-level atomic system near the plasmonic nanostructure

We theoretically investigate the possibility of controlling the high magneto-optical rotation without suffering an accompanying loss in transmission via the presence of a plasmonic nanostructure near the atomic five-level system. The key to optimization is the introduction of an additional degree of freedom by the location of the plasmonic nanostructure. We show that placing the plasmonic nanostructure at different distances from the atomic system allows arbitrary magneto-optical rotations with virtually 100% transmission. We numerically and analytically show that the existence of the plasmonic nanostructure near the atomic system leads to a strong adjustment of the optical properties of the quantum systems. We present a number of controlling parameters with emphasis on realizing 45° and 90° rotations in the proposed structure. The introduced model can exhibit great performances in converting TE-TM polarization and isolator applications.