Artificial gauge fields in photonics

Abstract

<p>Structured photonic systems, from photonic crystals to metamaterials and metasurfaces, provide a broad platform for photonic gauge fields. This artificial version of the real gauge fields in electrodynamics can induce a range of exotic functionalities in many branches of optical physics, enabling the manipulation of light and its interactions with various photonic structures in new and interesting ways. In this Review, we provide a viewpoint on how the concept of artificial gauge fields can connect seemingly unrelated optical effects. Artificial gauge fields in photonics can be either vectorial or scalar, Abelian or non-Abelian, real or complex. They apply not only to conventional real and momentum spaces, but also to spaces spanned by other synthetic dimensions, and are applicable to both semiclassical and quantum systems. In this Review, leveraging the wide applicability of the artificial gauge field, we connect different optical branches, including topological photonics, non-Abelian physics and non-Hermitian photonics. We discuss the current progress and next steps of research on optical gauge fields as well as their potential for future applications.<br></p>