FIrst NEar-TErm ApplicationS of QUAntum Devices

Project Information

FINE-TEA-SQUAD

Grant agreement ID: 101040729

DOI

10.3030/101040729

EC signature date 1 March 2022

Start date 1 May 2022

End date 30 April 2027

Funded under

• European Research Council (ERC)

Total cost

€ 1 485 042,50

EU contribution

€ 1 485 042,50

Coordinated by

UNIVERSITEIT LEIDEN
Netherlands

Periodic Reporting for period 1 - FINE-TEA-SQUAD (FIrst NEar-TErm ApplicationS of QUAntum Devices)

Reporting period: 2022-05-01 to 2024-10-31

Summary of the context and overall objectives of the project

Quantum computers could spur the development of new breakthroughs in science and technology. However, utilising their advantage requires breaking barriers in the development, optimization, and benchmarking of quantum algorithms. We are currently in the ‘noisy’ era of quantum computing with noisy intermediate-scale quantum (NISQ) processors. Such devices are limited in their ability to run textbook quantum algorithms. The EU-funded FINE-TEA-SQUAD project aims to develop a unifying framework that will enable NISQ devices to find practical applications. Researchers will design protocols for quantum state preparation and characterise broad families of states that can be prepared in a scalable way. They will also develop a practical certification toolset amenable to near-term devices, with a special focus on the generation of certified randomness from a single NISQ device.

The research in FINE-TEA-SQUAD is structured along three directions: (A) Design of experimentally friendly protocols for quantum state preparation, circumventing the major bottlenecks that exist in practice, with a special focus on the prohibitive number of measurements (e.g. in quantum-classical feedback loops). (B) Develop a practical certification toolset amenable to near-term devices, with especial focus on the generation of certified randomness from a single quantum device. (C) Formulate distributed quantum algorithmic tasks by combining several NISQ nodes into a small quantum network as a proposal to bypass current hardware scalability limitations, but also to explore the potential and limitations of these new, experimentally-motivated architectures in the context of quantum algorithms.

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

Up to now, the project has been successful, not only in exploring the research questions in the original proposal, but in identifying and exploring new, non-anticipated, yet also promising ones. Among the results obtained so far, we highlight here the (i) proposal for preparation of tensor network states in a quantum computer, along with techniques to yield provable success guarantees in terms its preparation runtime via the adiabatic algorithm, where we have laid the groundwork for the certification of their properties in a prover-verifier setting, (ii) we have provided the theoretical foundation for an experiment characterizing the depth of Bell correlations in a state-of-the-art superconducting 73-qubit chip, being the first of its kind, (iii) we have developed adiabtic spectroscopic techniques for more efficient adiabtic preparation of quantum states, (iv) we have obtained a series of results in the characterization of Bell nonlocality in multipartite systems, showcasing unforeseen connections to e.g. quantum chaos and dimension witnessing (v) we have developed several heuristical methods to make the most out of current quantum devices' possibilities, along with some rigorous proofs about their potential and limitations in some relevant instances.

All these achievements represent important steps towards the development of an appropriate theoretical framework to fully utilize the capabilities of current quantum devices.

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 project has pushed beyond the state-of-the-art in several directions. Here we highlight (i) We developed a novel algorithm that combines adiabatic and variational techniques for quantum state preparation that has already been utilized in experiments, thus demonstrating a significant practical impact. (ii) We introduced scalable methods for preparing and verifying tensor network states, which have inspired further ongoing research. (iii) We have achieved the first experimental demonstration of Bell correlation depth up to 24 particles in a state-of-the-art superconducting chip of 73 qubits, along with significant theoretical contributions in the multipartite characterization of quantum correlations.

FINE-TEA-SQUAD is primarily focused on fundamental research. Although future knowledge and technology transfer activities are possible, the results obtained so far do not seem to require immediate action in this area.