Unbounded Tellegen Response in Media with Multiple Resonances

Abstract

Tellegen response is a special type of nonreciprocal magneto-electric coupling which long remained elusive in photonics and extremely weak in condensed matter. It is widely accepted that the Tellegen coefficient is restricted by $\ddot{I}{‡}^2<\epsilon \hat{I}¼$, where $\epsilon$ and $\hat{I}¼$ are permittivity and permeability of the material. Here, we demonstrate that this restriction is lifted in the medium with several close resonances, which provides a theoretical foundation for giant Tellegen response.