Nonlinear Quantum Optics at a Topological Interface Enabled by Defect Engineering

TL;DR

This paper demonstrates the integration of quantum dots into topological photonic waveguides using defect engineering, enabling stable single-photon emission and spectroscopy at the interface, merging topological photonics with quantum nonlinear optics.

Contribution

It introduces a novel method for embedding quantum emitters into topological waveguides via defect engineering, facilitating quantum nonlinear optical experiments.

Findings

First single-photon resonant fluorescence at a topological interface

Resonant transmission spectroscopy of quantum emitters in topological waveguides

Successful integration of quantum dots with topological photonic structures

Abstract

The integration of topology into photonics has generated a new design framework for constructing robust and unidirectional waveguides, which are not feasible with traditional photonic devices. Here, we overcome current barriers to the successful integration of quantum emitters such as quantum dots (QDs) into valley-Hall (VH) topological waveguides, utilising photonic defects at the topological interface to stabilise the local charge environment and inverse design for efficient topological-conventional mode conversion. By incorporating QDs within defects of VH-photonic crystals, we demonstrate the first instances of single-photon resonant fluorescence and resonant transmission spectroscopy of a quantum emitter at a topological waveguide interface. Our results bring together topological photonics with optical nonlinear effects at the single-photon level, offering a new avenue to investigate the interaction between topology and quantum nonlinear systems.