Periodic Reporting for period 4 - QUSCO (Quantum superiority with coherent states)
Período documentado: 2022-07-01 hasta 2024-06-30
Quantum technologies explore the possibility of harnessing the power of quantum properties of physical systems to demonstrate in practice an advantage in terms of computational time, security or communication efficiency. Such an advantage can revolutionize current practices in information processing and communication, with a range of applications in financial, government and medical transactions, critical infrastructure protection, material design, network management, and many more. The deployment however of a large-scale quantum network connecting devices such as quantum computers or sensors that would be able to unlock the full potential of quantum resources may lie several years ahead. While we advance in this direction, it is crucial to demonstrate that current and near-term quantum technologies can already be exploited for enabling or enhancing useful tasks in a way that cannot be achieved by classical means.
In QUSCO, we pursued this objective using photonic systems, where information is typically encoded in properties of single or entangled photons. The photonic experimental platform is perfectly suited for communication of quantum information thanks to the inherent robustness of photons to losses during propagation. It can also be used currently for performing small-scale quantum computations and additionally provides a promising path to integration, which can drastically enhance the scalability of the resulting systems. Based on this technology and on a strong interaction between experimental physics and theoretical computer science, we conceived and implemented throughout the project advanced communication and computation tasks exhibiting a provable quantum advantage. Our demonstrations allow us to conclude that photonic quantum technologies can be used today for showing quantum advantage with practical resources for compelling applications, hence successfully achieving the primary objective of this action.
In QUSCO, we pursued this objective using photonic systems, where information is typically encoded in properties of single or entangled photons. The photonic experimental platform is perfectly suited for communication of quantum information thanks to the inherent robustness of photons to losses during propagation. It can also be used currently for performing small-scale quantum computations and additionally provides a promising path to integration, which can drastically enhance the scalability of the resulting systems. Based on this technology and on a strong interaction between experimental physics and theoretical computer science, we conceived and implemented throughout the project advanced communication and computation tasks exhibiting a provable quantum advantage. Our demonstrations allow us to conclude that photonic quantum technologies can be used today for showing quantum advantage with practical resources for compelling applications, hence successfully achieving the primary objective of this action.
In QUSCO, we studied both theoretically and experimentally a wide range of functionalities where quantum resources can be used to surpass the performance of classical systems, beyond unconditionally secure communication, which is the most well-known and studied application.
Our main achievements include the demonstration of such a quantum advantage for cryptographic tasks guaranteeing superior security for money transactions and coin flipping. Furthermore, we showed that it is possible to use efficiently quantum resources for performing a distributed computation task with limited available information – this is relevant for scenarios where some information needs to remain private. Finally, we developed theoretical and experimental tools enabling the certification of quantum resources, including untrusted channels or multipartite entangled states. Such tools determine whether quantum network users can trust the resources at hand to perform their intended task, making them a critical element for reliable operation of quantum networks.
Our work led to results published in 15 scientific publications and preprints and widely communicated to the scientific community but also to the media, general public and policy makers at workshops, conferences, industry panels and interviews with the press.
Our main achievements include the demonstration of such a quantum advantage for cryptographic tasks guaranteeing superior security for money transactions and coin flipping. Furthermore, we showed that it is possible to use efficiently quantum resources for performing a distributed computation task with limited available information – this is relevant for scenarios where some information needs to remain private. Finally, we developed theoretical and experimental tools enabling the certification of quantum resources, including untrusted channels or multipartite entangled states. Such tools determine whether quantum network users can trust the resources at hand to perform their intended task, making them a critical element for reliable operation of quantum networks.
Our work led to results published in 15 scientific publications and preprints and widely communicated to the scientific community but also to the media, general public and policy makers at workshops, conferences, industry panels and interviews with the press.
The experimental demonstrations achieved in QUSCO were all the first to show a quantum advantage for the tasks under study, and include a rigorous theoretical analysis and realistic implementation conditions. Importantly, they span an enhancement in performance in security, communication efficiency and computational time, and hence enrich substantially the available application pool for the emerging quantum networks. This was possible because of strong synergistic efforts at the interface between physics and computer science, which is a key element for further breakthroughs in quantum technology.