Journal Article

Highly indistinguishable and strongly entangled photons from symmetric GaAs quantum dots

Huang, Huiying, Schmidt, Oliver G., Huo, Yongheng, Wildmann, Johannes S., Huber, Daniel, Rastelli, Armando, Reindl, Marcus, Trotta, Rinaldo

2017

Overview

The development of scalable sources of non-classical light is fundamental to unlocking the technological potential of quantum photonics. Semiconductor quantum dots are emerging as near-optimal sources of indistinguishable single photons. However, their performance as sources of entangled-photon pairs are still modest compared to parametric down converters. Photons emitted from conventional Stranski–Krastanov InGaAs quantum dots have shown non-optimal levels of entanglement and indistinguishability. For quantum networks, both criteria must be met simultaneously. Here, we show that this is possible with a system that has received limited attention so far: GaAs quantum dots. They can emit triggered polarization-entangled photons with high purity (g (2) (0) = 0.002±0.002), high indistinguishability (0.93±0.07 for 2 ns pulse separation) and high entanglement fidelity (0.94±0.01). Our results show that GaAs might be the material of choice for quantum-dot entanglement sources in future quantum technologies. Scalable and integratable sources of entangled-photon pairs are an important building block for quantum photonic applications. Here, Huber et al . demonstrate that droplet-etched gallium arsenide quantum dots can emit highly indistinguishable photon pairs with a high degree of entanglement.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 639/624/399/1017 / 639/766/400/482 / 639/766/483/3925 / Humanities and Social Sciences / multidisciplinary / Science / Science (multidisciplinary)