Haldane Quantum Hall Effect for Light in a Dynamically Modulated Array of Resonators

TL;DR

This paper demonstrates how to induce the Haldane Quantum Hall effect for light in a lattice of optical resonators through dynamic modulation, resulting in robust one-directional edge states with potential for high-quality slow-light applications.

Contribution

It introduces a method to realize the Haldane Quantum Hall effect for light using on-site frequency modulation in resonator arrays, enabling topologically protected edge states.

Findings

Observation of one-directional edge states immune to back-scattering

Implementation of dynamic modulation to induce gauge fields for light

Potential for high-quality slow-light devices

Abstract

Topological insulators have attracted abundant attention for a variety of reasons -- notably, the possibility for lossless energy transport through edge states `protected' against disorder. Topological effects like the Quantum Hall state can be induced through a gauge field, which is however hard to create in practice, especially for charge-neutral particles. One way to induce an effective gauge potential is through a dynamic, time-periodic modulation of the lattice confining such particles. In this way, the Haldane Quantum Hall effect was recently observed in a cold atom system. Here, we show how this same effect can be induced for light confined to a lattice of identical optical resonators, using an on-site modulation of the resonant frequencies. We further demonstrate the existence of one-directional edge states immune to back-scattering losses, and discuss the possibilities for a practical implementation, which would enable slow-light devices of unprecedented quality.