Macroscopic quantum electrodynamics and duality in non-local and Onsager-violating media

TL;DR

This paper develops a comprehensive quantum electrodynamics framework for complex media, including non-local and Onsager-violating materials, highlighting the conditions under which electromagnetic duality symmetry is preserved or broken.

Contribution

It introduces a general quantization scheme for media without assuming Onsager reciprocity, incorporating non-local responses and duality invariance considerations.

Findings

Duality invariance holds as a continuous symmetry only with non-reciprocal responses.

A formulation based on conductivity tensor and Green tensor for non-local media.

Explicit duality-invariant scheme for local media with permittivity, permeability, and magnetoelectric susceptibilities.

Abstract

We formulate macroscopic quantum electrodynamics for the most general linear, absorbing media. In particular, Onsager reciprocity is not assumed to hold. For media with a non-local response, the field quantisation is based on the conductivity tensor and the Green tensor for the electromagnetic field. For a local medium response, we introduce the permittivity, permeability and magnetoelectric susceptibilities to obtain an explicitly duality-invariant scheme. We find that duality invariance only holds as a continuous symmetry when non-reciprocal responses are allowed for.