Unusual electromagnetic scattering by cylinders of topological insulator.

Topological insulators (TIs) show unusual optical responses resulting from a topological magnetoelectric (TME) effect. In this paper, we study theoretically the scattering of electromagnetic waves by circular TI cylinders. In certain configurations, the bulk scattering can be suppressed, leading to strong scattering in the backward direction in both Rayleigh and Mie scattering regimes due to the TME effect. At antiresonances, an interesting filed trapping phenomenon is found which is absent in conventional dielectric cylinders.