Bright electrically contacted circular Bragg grating resonators with deterministically integrated quantum dots

TL;DR

This paper presents a novel electrically contacted circular Bragg grating resonator with integrated quantum dots, achieving high photon extraction efficiency, tunable emission, and high single-photon purity, advancing quantum photonic device development.

Contribution

It introduces a new ridge-based electrically-contacted CBG resonator with deterministic quantum dot integration and optimized electro-optical properties, improving photon extraction and purity.

Findings

Photon extraction efficiency up to 30.4%

Single-photon purity of 98.8%

Photon indistinguishability of 25.8%

Abstract

Cavity-enhanced emission of electrically controlled semiconductor quantum dots is essential in developing bright quantum devices for real-world quantum photonic applications. Combining the circular Bragg grating (CBG) approach with a PIN-diode structure, we propose and implement an innovative concept for ridge-based electrically-contacted CBG resonators. Through fine-tuning of device parameters in numerical simulations and deterministic nanoprocessing, we produced electrically controlled single quantum dot CBG resonators with excellent electro-optical emission properties. These include multiple wavelength-tunable emission lines and a photon extraction efficiency (PEE) of up to (30.4$\pm$3.4)%, where refined numerical optimization based on experimental findings suggests a substantial improvement, promising PEE >50%. Additionally, the developed quantum light sources yield single-photon purity reaching (98.8$\pm$0.2)% [post-selected: (99.5$\pm$0.3)%] and a photon indistinguishability of (25.8$\pm$2.1)% [post-selected: (92.8$\pm$4.8)%]. Our results pave the way for high-performance quantum devices with combined cavity enhancement and deterministic charge-environment controls, advancing the development of photonic quantum information systems such as complex quantum repeater networks.