in WP 1 the partners successfully developed new theoretical tools for quantum optimal control (QOC) and improved upon existing ones. The results here obtained were also applied to the other, more experiment-drive. WP Highlights include findings on the controllability of rotating molecules with applications to the sensing of chiral molecules, and the improvement of the optimisation suite “RedCRAB” with applications to the generation of a 20-qubit entangled state of Rydberg atoms.
among the exploitable results, The work by Diaz et all (PRA 102 -2020) is relevant for the superiority of the quantum speed limit (QSL) and is a step forward in the understanding of the link between QSLs and optimal control.
WP2 explored how individual ensembles of quantum systems can be used to measure a classical quantity, and how quantum state engineering and QOC can be used to achieve this goal more efficiently. Open-loop control was used in magnetic resonance to overcome transients in quantum-limited EPR spectroscopy. QOC has been used to devise RF and microwave pulse sequences aiming at preparing Rydberg atoms in a non-classical superposition of states. QOC has been applied to design pulses that overcome the spatial inhomogeneity of the microwave field applied to the spins. These pulses extended the field of view of micrometer scale magnetic resonance imaging of nuclear spins deposited on diamond. Moreover, we improved the sensitivity of nuclear magnetic resonance imaging (MRI) down to the nanoscale using quantum sensors, observed genuine two atom interference, and used Single Microwave Photon Detector to demonstrate the first spin detection based on fluorescence
On the front of the exploitable results, The strongly hyperpolarized samples could be used to improve MRI measurements and increase the sensitivity of shallow NV centers.
in WP 3 we have been developing a quasi-particle tomography for quantum fields describing the evolution of many-body systems and a general pathway to extract the irreducible building blocks and its parameters of quantum field theoretical descriptions from experimental data.
We have developed an improved closed-loop tune-up method allowing for the simultaneous tune-up of an arbitrary set of pulse parameters to achieve high fidelity control pulses with multiple (correlated) parameters. Additionally, we have been developing a software package that will ultimately include both the calibration code as well as the simulation capabilities in an open-source software package, allowing for optimal control measurements as well as system identification.
For WP 4 all planned training events have been successfully implemented and the results of the surveys for each event analysed. On the basis of these activities, QuSCo has prepared a white paper on education in QT.
Concerning WP 5, our students have successfully developed outreach tools and tested them in specific events. QuSCo has also created 3 promotional videos (available on youtube). Finally, the games “Quantum Moves 2” and the App “Spindrop” have been published. All the results indicated have clear exploitation potential.
With 22 publications, 8 of which are in high impact journals and 12 more manuscripts currently under peer-review, QuSCo has fully achieved its scientific goals.
