Mode Delocalization in Disordered Photonic Chern Insulator

TL;DR

This paper demonstrates the existence of delocalized bulk eigenstates in disordered photonic Chern insulators through a realistic model, highlighting the role of resonator losses and ensemble averaging in experimental observation.

Contribution

It introduces a method to observe bulk delocalized states in disordered photonic Chern insulators using a tight-binding model with loss management and ensemble techniques.

Findings

Delocalized bulk states exist up to a critical disorder strength.

Selective resonator losses suppress edge states for clearer observation.

Large ensemble sizes are necessary for experimental detection.

Abstract

In disordered two dimensional Chern insulators, a single bulk extended mode is predicted to exist per band, up to a critical disorder strength; all the other bulk modes are localized. This behavior contrasts strongly with topologically trivial two-dimensional phases, whose modes all become localized in the presence of disorder. Using a tight-binding model of a realistic photonic Chern insulator, we show that delocalized bulk eigenstates can be observed in an experimentally realistic setting. This requires the selective use of resonator losses to suppress topological edge states, and acquiring sufficiently large ensemble sizes using variable resonator detunings.