Optical Tellegen metamaterial with spontaneous magnetization

Shadi Safaei Jazi; Ihar Faniayeu; Rafael Cichelero; Dimitrios C Tzarouchis; Mohammad Mahdi Asgari; Alexandre Dmitriev; Shanhui Fan; Viktar Asadchy

doi:10.1038/s41467-024-45225-y

Optical Tellegen metamaterial with spontaneous magnetization

Nat Commun. 2024 Feb 12;15(1):1293. doi: 10.1038/s41467-024-45225-y.

Authors

Affiliations

¹ Department of Electronics and Nanoengineering, Aalto University, P.O. Box 15500, FI-00076, Aalto, Finland.
² Department of Physics, University of Gothenburg, Gothenburg, 41296, Sweden.
³ Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA.
⁴ Meta Materials Europe, Marousi, 15123, Athens, Greece.
⁵ Ginzton Laboratory and Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA.
⁶ Department of Electronics and Nanoengineering, Aalto University, P.O. Box 15500, FI-00076, Aalto, Finland. viktar.asadchy@aalto.fi.
⁷ Ginzton Laboratory and Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA. viktar.asadchy@aalto.fi.

^# Contributed equally.

Abstract

The nonreciprocal magnetoelectric effect, also known as the Tellegen effect, promises a number of groundbreaking phenomena connected to fundamental (e.g., electrodynamics of axion and relativistic matter) and applied physics (e.g., magnetless isolators). We propose a three-dimensional metamaterial with an isotropic and resonant Tellegen response in the visible frequency range. The metamaterial is formed by randomly oriented bi-material nanocylinders in a host medium. Each nanocylinder consists of a ferromagnet in a single-domain magnetic state and a high-permittivity dielectric operating near the magnetic Mie-type resonance. The proposed metamaterial requires no external magnetic bias and operates on the spontaneous magnetization of the nanocylinders. By leveraging the emerging magnetic Weyl semimetals, we further show how a giant bulk effective magnetoelectric effect can be achieved in a proposed metamaterial, exceeding that of natural materials by almost four orders of magnitude.