Leveraging Quantum Control to Reveal Hidden Quantities

Quantum technologies promise breakthroughs by harnessing the unique properties of quantum physics. However, some of the resources that make quantum technologies powerful lack reliable ways to measure and compare them. Our project develops practical benchmarks for two of them: modular quantum processes, which expand what quantum computers can do, and continuous-variable entanglement, investigating infinite-dimensional systems. By creating and testing application-oriented benchmarking protocols, we aim to accelerate the integration of these resources into future quantum technologies. Benchmarks help to compare techniques, track progress, and reveal advantages across different platforms, such as superconducting qubits or NV centres. The first emerging resource we benchmark is designed to extend quantum computation beyond the standard circuit model: modular quantum processes. These higher-order processes include the if-then-loops of quantum coding and counterintuitive protocols where the order of the circuit elements themselves is in a quantum superposition. Staring from coherent controlisation, we will look for more general protocols, as well as ways to reduce their measurement complexity to simplify their implementation. Secondly, we tackle continuous-variable entanglement, which promises to allow the exploitation of the complexity of infinite-dimensional systems for sensing and quantum communication. Here, we will investigate how discretisation techniques beyond the Gaussian state approximation can be adapted to fit specific measurement setups. By creating consistent and practical ways to measure these resources, grounded in quantum information theory, we will enable fair comparisons across platforms and provide guidance on where their strengths lie.