Periodic Reporting for period 1 - VeriQuB (Efficient Verification of Quantum computing architectures with Bosons)
Reporting period: 2023-09-01 to 2024-08-31
Quantum information processing offers significant advantages over classical methods, especially in computation, cryptography, communication, and sensing. Recently, alternative approaches using bosons as information carriers have gained traction due to their potential for fault-tolerance and scalability. For instance, bosonic modes of light enable the generation of large entangled quantum states, while superconducting microwave fields provide avenues for quantum error correction. Quantum devices can only realize their full potential if they operate with high precision. Quantum verification ensures the correct functioning and accuracy of these devices, which is crucial for their effective use. As quantum devices become more accessible, robust verification methods will be essential for maintaining the privacy and integrity of quantum computations for end-users.
The urgency for efficient quantum verification methods is underscored by the need to demonstrate the first major quantum advantage (quantum speedup), is a milestone in the development of quantum computers. Despite ongoing efforts, achieving verified quantum speedup remains challenging. Efficient and rigorous verification thus remains a bottleneck in demonstrating quantum speedup and in scaling up quantum computers to solve real-world problems.
Quantum verification protocols typically involve numerous measurements of a device’s output to analyse its performance. However, general-purpose methods like tomography require impractically large numbers of measurements. This presents a major obstacle to the development of large-scale quantum technologies. Alternative approaches are therefore required.
In 2020, a theoretical breakthrough by the project coordinator led to the following idea: large bosonic quantum devices can be verified efficiently using continuous-variable (CV) quantum measurements, avoiding the exponential cost in terms of measurement samples. Although further development is needed to make these methods practical, this hints at the possibility of developing practical and efficient quantum verification methods for bosonic quantum computing architectures based on CV measurements. These measurements are already used in state-of-the-art quantum cryptography and communication protocols, but are rarely applied to quantum verification and computing.
The VeriQuB consortium will develop a state-of-the-art verification toolbox consisting of two main components: (1) an experimental demonstration of the verification of multimode bosonic systems for both optical and superconducting architectures, including the first verified quantum computational speedup; and (2) a theoretical framework outlining the fundamental advantages of VeriQuB’s contributions while identifying resourceful bosonic quantum devices.
Website: https://veriqub.eu(opens in new window)
The urgency for efficient quantum verification methods is underscored by the need to demonstrate the first major quantum advantage (quantum speedup), is a milestone in the development of quantum computers. Despite ongoing efforts, achieving verified quantum speedup remains challenging. Efficient and rigorous verification thus remains a bottleneck in demonstrating quantum speedup and in scaling up quantum computers to solve real-world problems.
Quantum verification protocols typically involve numerous measurements of a device’s output to analyse its performance. However, general-purpose methods like tomography require impractically large numbers of measurements. This presents a major obstacle to the development of large-scale quantum technologies. Alternative approaches are therefore required.
In 2020, a theoretical breakthrough by the project coordinator led to the following idea: large bosonic quantum devices can be verified efficiently using continuous-variable (CV) quantum measurements, avoiding the exponential cost in terms of measurement samples. Although further development is needed to make these methods practical, this hints at the possibility of developing practical and efficient quantum verification methods for bosonic quantum computing architectures based on CV measurements. These measurements are already used in state-of-the-art quantum cryptography and communication protocols, but are rarely applied to quantum verification and computing.
The VeriQuB consortium will develop a state-of-the-art verification toolbox consisting of two main components: (1) an experimental demonstration of the verification of multimode bosonic systems for both optical and superconducting architectures, including the first verified quantum computational speedup; and (2) a theoretical framework outlining the fundamental advantages of VeriQuB’s contributions while identifying resourceful bosonic quantum devices.
Website: https://veriqub.eu(opens in new window)
Ongoing scientific discussions in the consortium experts have yielded promising results across all WPs. Key resources are being identified, with partners developing single-mode witnesses for stellar rank (a known quantifier of bosonic resources) and a framework to analyse Gaussian conversion protocols between quantum non-Gaussian resource states. These developments are crucial for both optical and superconducting platforms. For superconducting experimental platforms, partners have developed a theoretical proposal and are working on the implementation of the qubitdyne protocol in 3D cavities. For optical platforms, efforts are focused on verifying stellar rank and Wigner negativity for single-mode photon-subtracted states.
Project management and coordination are well-established and, over the past months, VeriQuB actively contributed to the Portfolio “Alternative Quantum Information Processing, Communication and Sensing” (AQIPCS), which seeks to explore and leverage alternative quantum principles for future systems.
Project management and coordination are well-established and, over the past months, VeriQuB actively contributed to the Portfolio “Alternative Quantum Information Processing, Communication and Sensing” (AQIPCS), which seeks to explore and leverage alternative quantum principles for future systems.
At this stage of the project, preliminary results are being obtained by all partners and contribute to establishing a theory toolbox for verification of bosonic quantum computing architectures of practical relevance.
The potential impacts of such a toolbox are:
- For academics: it will foster a significant amount of follow-up work, both during and beyond VeriQuB. The interdisciplinarity of the VeriQuB project already leads to a novel transfer of know-how between quantum optics and circuit QED communities. We also envision our project as an important enabler for other research efforts within the AQIPCS portfolio;
- For industrial actors: VeriQuB will enable laying out an innovation roadmap for bosonic quantum computing, and its exploration of multiple bosonic architectures can provide promising pathways to large-scale quantum computing;
- For end users: the general public and investors are currently trying to figure out whether they could benefit from the onset of quantum technologies. Similarly, rigorous quantum benchmarks are essential to inform investment decisions. In this context, VeriQuB's methods will enable European industries to have early access to large-scale bosonic quantum computing with verified quantum advantage, giving them a significant competitive edge in many types of industries. Moreover, investors and their own end users will gain trust in quantum technologies, fostering growth in terms of usage of these technologies in Europe;
- For policy makers: in the longer term, the rigorous fidelity witness metrics introduced in our project could become part of a larger European-led effort for benchmark standardisation.
The potential impacts of such a toolbox are:
- For academics: it will foster a significant amount of follow-up work, both during and beyond VeriQuB. The interdisciplinarity of the VeriQuB project already leads to a novel transfer of know-how between quantum optics and circuit QED communities. We also envision our project as an important enabler for other research efforts within the AQIPCS portfolio;
- For industrial actors: VeriQuB will enable laying out an innovation roadmap for bosonic quantum computing, and its exploration of multiple bosonic architectures can provide promising pathways to large-scale quantum computing;
- For end users: the general public and investors are currently trying to figure out whether they could benefit from the onset of quantum technologies. Similarly, rigorous quantum benchmarks are essential to inform investment decisions. In this context, VeriQuB's methods will enable European industries to have early access to large-scale bosonic quantum computing with verified quantum advantage, giving them a significant competitive edge in many types of industries. Moreover, investors and their own end users will gain trust in quantum technologies, fostering growth in terms of usage of these technologies in Europe;
- For policy makers: in the longer term, the rigorous fidelity witness metrics introduced in our project could become part of a larger European-led effort for benchmark standardisation.