European Photonic Quantum Computer

Project Information

EPIQUE

Grant agreement ID: 101135288

DOI

10.3030/101135288

EC signature date 15 November 2023

Start date 1 January 2024

End date 31 December 2026

Funded under

• Digital, Industry and Space

Total cost

€ 10 340 741,50

EU contribution

€ 10 340 741,50

Coordinated by

UNIVERSITA DEGLI STUDI DI ROMA LA SAPIENZA
Italy

Periodic Reporting for period 1 - EPIQUE (European Photonic Quantum Computer)

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

Summary of the context and overall objectives of the project

EPIQUE project aims at building a European quantum computer based on scalable photonic technology. Photonic systems, due to their inherent properties of high resilience to decoherence and capability of long-distance propagation, have been at the forefront of several quantum information tasks. The project activities will be dedicated to developing the full stack towards the realization of systems based on the measurement-based quantum computation paradigm, from hardware and software components to the assembly of full quantum machines accompanied with verification tools. More specifically, the consortium has identified three key objectives.
The first objective is dedicated to the goal of achieving significant advances in the main specifications of photon sources. We will focus on deterministic single photons emitters via quantum dots, deterministic sources of linear cluster states, and squeezed light sources. All these classes of sources are relevant to implement measurement-based quantum computing architectures. Furthermore, work will be carried out to increase the operating speed of discrete and integrated nanowire single photon detectors, and of integrated homodyne detectors, while preserving or improving the corresponding detection efficiencies.
The second objective aims at developing and optimizing all necessary circuit components for single-photon manipulation. These will include modulators, switches, mux/demuxers, delay lines and active feed-forward, as well as improving the performances of three different PIC (Photonic Integrated Circuit) platforms. This approach will exploit the advantages of each platform. The final step will be to assemble three different prototypes that will differentiate between the diversified approaches of the project to analyze the potential of each individual architecture.
Finally, the last objective will be dedicated to the development of software, computing architectures and efficient benchmarking methods to cover all level of computational stack. This will allow to optimize the computational capabilities of the developed technology, its robustness to noise, and demonstrate modularity for scalability towards large-scale fault-tolerance. Furthermore, the benchmarking methods will be employed to validate the photonic approach to quantum computing.

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

Regarding the hardware development, several results were achieved in the development of squeezed sources with high squeezing level and efficiency, as well as improvements for single-photon emitters, both in terms of efficiency and interference between remote emitters. Fabrication of integrated circuits for photon manipulations is also currently carried out with all the three main platforms used within the project. Active manipulation components have also been developed, ranging from integrated switches, time-to-spatial demultiplexer modules, and implementation of fast feed-forward systems. Finally, progress has been made in the development of single-photon detectors, including high efficiency systems, waveguide integrated detectors, and high-speed, high-efficiency homodyne detectors. All these components will become part of the assembled machines in the second part of the project. The assembly of the machines have also kicked off in this first part of the EPIQUE project. The architecture for all machines has been defined, and the process to interface the different components in each single machine has started.
Regarding the software part, the consortium has analyzed different photonic quantum computation architectures obtaining several relevant results, in particular on non-universal models for near-term quantum computing and for the generation of GHZ states, as testified by the number of preprint/publications obtain in the period. These results have been also part of the background to define the architecture for the machines. On the verification side, the consortium has developed several benchmarking methods useful to validate the output of quantum computations. These include hardware-specific benchmarking protocols, new measures of non-classicality, and first work to merge all the developed methods in a unique standard for the system validation. Finally, the consortium has also started to identify and develop quantum algorithms that exploit photonic quantum computing machines for practical applications, following two approaches: adapting protocols designed for qubit-based systems, or directly devising approaches which natively fit for photonic systems.

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)

The main achievements reported above correspond to advances in photonic components and software beyond the current state of the art. More specifically, current results in photon sources led to improved performances for the employed technologies, including the important milestone of demonstrating quantum interference with remote quantum dot emitters. Analogously, the work carried out for all integrated photonic platforms, active components, and detectors is leading to improving the performances of each specific hardware element. Beyond state-of-the-art performances will be pivotal for the machine assembly in the second part of the project. In parallel, all the theoretical work has led to novel methodologies for system benchmarking, a crucial step for the verification of quantum computing at all levels.
The scientific results of the projects have also led to identification of a list of innovations, ranging from the aforementioned novel components to the full machines which represent the expected final outcome of the project. For these innovations, the consortium has started to evaluate all the necessary steps to identify their potential for an eventual commercialization. For some of these innovations, IPR protection measures have been kicked off since 5 patent applications have been submitted. The subsequent steps that will be carried out will then be a thorough market analysis for all products, to evaluate commercialization potential, and further steps to move the status of these innovations to a high level of technological maturity.

Kick-off meeting in Rome

EPIQUE logo