Hyperbolic Weyl point in reciprocal chiral metamaterial

TL;DR

This paper demonstrates the existence of Weyl points in reciprocal chiral metamaterials with broken inversion symmetry, showing their physical realization and classification into type-I or type-II based on non-local responses.

Contribution

It introduces a new class of non-centrosymmetric metamaterials with Weyl points and provides a practical design for realizing type-II Weyl points.

Findings

Weyl points exist in reciprocal chiral metamaterials with time reversal symmetry.

The metamaterials can exhibit either type-I or type-II Weyl points.

A physical realization using elliptical helix-shaped metal wires is demonstrated.

Abstract

We report the existence of Weyl points in a class of non-central symmetric metamaterials, which has time reversal symmetry, but does not have inversion symmetry due to chiral coupling between electric and magnetic fields. This class of metamaterial exhibits either type-I or type-II Weyl points depending on its non-local response. We also provide a physical realization of such metamaterial consisting of an array of metal wires in the shape of elliptical helixes which exhibits type-II Weyl points.