Scalable Quantum Photonic Networks

Project Information

SCALE

Grant agreement ID: 669758

DOI

10.3030/669758

Project closed

EC signature date 7 September 2015

Start date 1 December 2015

End date 30 November 2020

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 2 499 981,00

EU contribution

€ 2 499 981,00

Coordinated by

KOBENHAVNS UNIVERSITET
Denmark

Periodic Reporting for period 4 - SCALE (Scalable Quantum Photonic Networks)

Reporting period: 2020-06-01 to 2020-11-30

Summary of the context and overall objectives of the project

The quest of SCALE is to study and develop quantum photonics hardware towards long-term and transformative applications based on large-scale quantum networks comprising multiple light and matter quantum bits. Fundamental quantum light-matter building blocks with high performance have been constructed and are continuously improved even further. The exciting challenge is to scale these systems up to large and complex quantum architectures. An immediate goal has been to deliver a photonic quantum resource that is capable of encoding more information than the world’s largest classical computer can handle. This benchmark of Quantum Advantage has been realized within SCALE using quantum dot single-photon sources based on nanophotonic waveguides. Furthermore, more advanced functionalities have been implemented and studied, notably the generation of on-demand spin-photon entanglement and single-photon nonlinear optics. This hardware paves the way for novel applications within secure quantum communication, quantum repeaters, and photonic quantum simulators.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The main scientific highlights include:
* Demonstration of a single-photon source enabling reaching Quantum Advantage. The paper is accepted in Science Advances (publication date Dec. 9th, 2020), a press release has been issued and the associated press coverage is taking place.
* Demonstration of on-demand spin-photon entanglement and as a next step on-demand and scalable multi-photon entanglement generation. The experiment is currently being completed. (Paper accepted in Phys. Rev. Lett. and another high-profile manuscript is in preparation).
* Demonstration of single-photon nonlinear optics with a quantum dot including studies of the complex dynamical properties (paper in review at Phys. Rev. Lett. + 2 additional high-profile publications are in preparation)
* Formulation of a blueprint for a one-way quantum repeater based on quantum dot hardware (Physical Review X, 2020)
* Demonstration of a plug-and-play single-photon source based on a dual-mode waveguide (Nature Communications, 2020)
* Demonstration of a photonic switch controlled by a single spin in a quantum dot. (Nature Nanotechnology, 2018)

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

SCALE has advanced quantum dot single-photon sources and functionalities significantly beyond state-of-the-art and proven that these systems are scalable and mature for tackling advanced quantum applications. New quantum photonics building blocks have been realized and their performance improved, and the governing figures-of-merits identified. Proof-of-concept scaling-up experiments have been realized and blueprints of how to resource-efficiently apply the hardware in advanced quantum communication have been put forward. Today the quantum-dot single-photon sources start to become commercially viable. To this end, the PI is the founder of the spin-out company Sparrow Quantum.

Single-photon source developed in SCALE that is capable of reaching Quantum Advantage.