Bright Electrically Contacted Circular Bragg Grating Resonators with Deterministically Integrated Quantum Dots.

Abstract

Cavity-enhanced emission of electrically controlled semiconductor quantum dots (QDs) is essential in the development of 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 designs for ridge-based electrically contacted QD-CBG resonators. Through fine-tuning of device parameters in numerical simulations and deterministic nanoprocessing, we produced electrically controlled single QD-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(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 99.2(2)% and photon indistinguishability of 75(5)% under quasi-resonant p-shell excitation. Our results present high-performance quantum devices with combined cavity enhancement and deterministic charge-environment controls, which are relevant for the development of photonic quantum information systems such as complex quantum repeater networks.