Quantized Hall drift in a frequency-encoded photonic Chern insulator

TL;DR

This paper demonstrates a novel method to realize photonic Chern insulators using frequency-encoded topological models in optical fibers, enabling robust light transport for advanced photonic applications.

Contribution

It introduces a new approach to create topological photonic insulators by encoding a Haldane-like model in the frequency domain of an optical fiber system.

Findings

Reconstructed Bloch states across the Brillouin zone.

Measured a quantized Hall-like transverse conductivity.

Showed topologically protected light propagation in frequency space.

Abstract

The quantization of transport and its resilience to backscattering are key features for leveraging topological matter in applications that demand stringent noise mitigation, such as metrology and quantum information processing. Due to the bosonic nature of light, engineering such robust, ``one-way'' channels in synthetic photonic systems imposes the implementation of topological models with broken time-reversal symmetry; this is challenging since photons possess neither an electric charge nor a magnetic moment. Here, we propose and demonstrate a novel approach to realizing photonic Chern insulators - topological insulators with broken time-reversal symmetry - by encoding a Haldane-like model in the synthetic frequency dimension of an optical fiber loop platform. The bands' topology is assessed by reconstructing the Bloch states geometry across the Brillouin zone. We further highlight its consequences by measuring a driven-dissipative analogue of the quantized transverse Hall conductivity. Our results open new avenues for harnessing topologically protected light propagation in frequency-multiplexed photonic systems, with applications ranging from precision metrology to photonic quantum processors.