Realization of magneto-optical near-zero-index metamaterial by using an array of spinning cylinders

Abstract

Magneto-optical materials have found wide applications in optical-functional devices and topological photonics due to their magneto-optical activity and time-reversal symmetry breaking. However, there are rare kinds of magneto-optical materials in nature and their working frequencies are mostly limited to the microwave regime which largely limits the applications. In this work, we propose a scheme to realize an effective magneto-optical near-zero-index metamaterial, that is, using an array of spinning cylinders. The material of the cylinder can be arbitrary and the strength of the magneto-optical effect parameter can be tuned according to the spinning speed. Therefore, the operating frequency can go beyond the microwave regime and in principle cover much higher frequencies, which largely expands the range of operating frequency of magneto-optical materials. The results are verified by numerical full-wave simulations.