Topological Optical Chirality Dichroism

TL;DR

This paper introduces a universal topological dichroism in 3D chiral systems, linking optical chirality to topological invariants, and proposes an experimental setup using superchiral light to detect chiral band topologies.

Contribution

It reveals how topological invariants cause quantized dichroic responses and proposes a novel optical method to probe chiral electronic topologies in materials.

Findings

Chiral topological invariants lead to integer-quantized dichroic excitation differences.

Topological effects arise from coupling optical chirality to higher tensor Berry curvatures.

An experimental setup with superchiral light can detect chiral band topologies.

Abstract

We report on a universal topological dichroism of chiral three-dimensional systems in response to the chirality of light. We show that chiral topological invariants result in integer-quantized dichroic excitation rate differences. Moreover, we demonstrate that such topological effects arise more generally from coupling optical chirality to higher tensor Berry curvatures and Dixmier-Douady invariants of quantum states, including Hopf indices. We finally propose an experimental setup that leverages superchiral light as a smoking-gun probe of chiral band topologies in three-dimensional materials. Our findings establish an optical route for probing to date unobserved chiral electronic band topologies.