Multi-Qubit Photonic Devices

Project Information

MultiQubit

Grant agreement ID: 101003378

DOI

10.3030/101003378

EC signature date 17 May 2021

Start date 1 June 2021

End date 31 January 2028

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 2 587 745,00

EU contribution

€ 2 587 745,00

Coordinated by

DANMARKS TEKNISKE UNIVERSITET
Denmark

Periodic Reporting for period 3 - MultiQubit (Multi-Qubit Photonic Devices)

Reporting period: 2024-06-01 to 2025-11-30

Summary of the context and overall objectives of the project

If you thought that computers and the Internet influenced the world drastically, imagine a future where quantum computers and quantum Internet are solving some of our society’s key challenges that seem to be impossible today — fast drug development, unbreakable information security, drastic energy saving, as well as 100% anonymous and secure elections are only a few examples.

Quantum computers are already just around the corner. Yet, the most advanced quantum computers today exploit superconducting qubits, which, unfortunately, do not have a native photonic interface, so they cannot be interconnected over long distances.

This MultiQubit project is committed to creating a robust technological platform for making solid-state multi-qubit devices with a photonic interface that could later become a platform for a quantum network, facilitate truly 100% secure communications, and save us a lot in energy costs.

Through the exploration and demonstration of a novel location qubit, based on crystal-phase quantum dots, the project will attain designable and scalable quantum systems grown with atomic precision, followed by a multi-qubit register with a photonic interface.

These quantum registers will then be used in a prototype application of a quantum information network, or the quantum Internet, the likes of which has never been seen before!

These new advancements along with the eventual creation of quantum networks would trigger the transformation of countless industries.

MultiQubit — laying down the foundation for the future of the quantum Internet.


See the explanatory video here: https://www.youtube.com/watch?v=U2ykvJ9vsdI

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

We have so far:
— Conceived a novel type of qubit — the location qubit.
— Developed a novel all-optical method of operating multi-qubit devices based on crystal-phased quantum dots.
— Simulated the performance of all-optical quantum gates in our multi-qubit devices.
— Established device fabrication process at C2N.
— Conceived the experimental setup for demonstrating and operating the location qubits.
— Designed and ordered the major equipment for building the experimental setup at DTU.
— Participated in a number of international conferences, workshops, and summer schools, describing our results through invited talks, research seminars, and posters.
— Published scientific papers on the results of the project.

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)

Our results so far — a novel location qubit and a novel all-optical method of operating multi-qubit devices — pave a clear way towards constructing multi-qubit solid-state quantum systems with a built-in photonic interface. One example is a multi-qubit quantum register — a fundamental building block of the forthcoming quantum internet.

By the end of the project, we aim to:
1. Experimentally demonstrate a controllably grown crystal-phase quantum dot with excellent optical properties.
2. Experimentally demonstrate a novel location qubit.
3. Experimentally demonstrate a multi-qubit device, based on location qubits.
4. Experimental demonstration of a basic prototype of the quantum Internet, based on our multi-qubit devices.
5. Patent and commercialize our innovations. For instance, create a spin-out company.

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