External seminar | 08 October 2024

Effective axion response also known as Tellegen response is a special type of magneto-electric coupling which arises in some materials with broken P and T symmetries and manifests itself only at the boundary of the medium, but not in the bulk. Due to this subtle property, the very existence of Tellegen response was long debated in electromagnetic community. By now, the existence of axion response is well established in a broad range of materials including magnetoelectrics, multiferroics and strong 3D topological insulators.

In this talk, I will introduce a simple model of multilayered metamaterial illustrating the origins of effective axion response in antiferromagnetic structures and discuss other recent proposals to realize Tellegen metamaterial. Next, I will introduce our recent prediction of a novel type of electromagnetic response closely resembling Tellegen and having the same symmetry properties, but distinct from it and described by the electrodynamics with magnetic charge.

Relevant papers: Link

DOI: 10.1103/PhysRevB.108.115101