Project: Quantum Dots for Entanglement-based Quantum Key Distribution

Acronym QD-E-QKD
Duration 02/05/2022 - 01/05/2025
Project Topic Entanglement is a fundamental ingredient for extending quantum key distribution from twoparty communication to networks without trusted nodes. Yet, the commercial application of this concept is currently hindered by the probabilistic nature of the photon-generation process underlying the used entanglement resources. QD-E-QKD will develop a novel technology based on semiconductor quantum dots and test it in realistic urban communication scenarios to surpass the limits of current approaches to entanglement-based quantum key distribution. Our photonic source will combine recent research developments in microfabrication in a single device. Its structural design will embed high-quality epitaxial quantum dots and include a p-i-n-i-n diode for the suppression of charge noise, a circular Bragg grating cavity for brightness enhancement, and a piezoelectric substrate for optimal entanglement. We predict that our device will operate—at near-unity degree of entanglement—at rates that are more than one order of magnitude higher that those accessible by state-of-the-art parametric down converters for the same qubit error rate. At the same time, the nearzero multi-pair emission probability guarantees better robustness against channel attenuation losses in the communication protocol implementation. We will use this device to implement quantum key distribution using two quantum-channel approaches, a single-mode fiber and free space. To guarantee stable operation we will develop a stand-alone device that combines time-to-digital conversion with optical clock recovery for remote synchronization and a free space-optical-communication receiver with integrated adaptive optics based on deformable lenses. Finally, we will provide quantitative benchmarking, backed by theoretical modelling and testing, to certify the advancement over existing entanglement-based quantum key distribution systems. This will offer a viable technology for the realization of more complex quantum key distribution networks.
Network QuantERA II
Call QuantERA II Call 2021

Project partner

Number Name Role Country
1 Sapienza Università di Roma Coordinator Italy
2 Stefano Bonora Partner Italy
3 University of Wuerzburg Partner Germany
4 Quantum Technology Laboratories Deutschland GmbH Partner Germany
5 Johannes Kepler University / Institute of Semiconductor & Solid State Physics Partner Austria
6 Quantum Technology Laboratories GmbH Austria Partner Austria
7 Palacký University, Olomouc Partner Czech Republic