MOQS has made substantial progress toward its scientific and training objectives. The consortium advanced quantum algorithms, hardware control, and simulation methods that jointly demonstrate how quantum resources can address complex problems in chemistry and materials science. In WP1 and WP3, major achievements were realised in the design and benchmarking of Variational Quantum Eigensolver (VQE) and time-dependent variational algorithms, validated both numerically and on IBM superconducting hardware. Building on RP1 results, algorithmic developments now allow efficient treatment of strongly correlated and time-dependent systems. Publications in Physical Review Research, PRX Quantum, and Nature Communications documented these advances, including corrections for finite-size and frustration effects in many-particle simulations. The open-source Qiskit–CP2K interface created in WP1 enables hybrid quantum–classical workflows combining density-functional theory with near-term quantum processors, fulfilling Deliverables D1.2 and D1.3.
Research under WP2 and WP3 focused on quantum hardware and control. Experiments on Rydberg-atom platforms demonstrated high-fidelity multi-qubit operations and the first mid-circuit erasure conversion in metastable neutral-atom qubits (Nature 2023). Complementary work on superconducting circuits achieved generalised quantum measurements (POVMs) without ancillary qubits, exploiting higher transmon states for improved readout and noise mitigation (Physical Review A 2024). Theoretical studies delivered time-optimal and noise-robust control strategies using gradient-based and machine-learning-assisted optimisation, reducing decoherence and improving gate fidelities beyond the DoA targets (Quantum, Physical Review A 2024).
In WP4, the project demonstrated integrated quantum simulations relevant to chemistry and energy-transfer dynamics. Pulse-level VQE algorithms implemented on IBM superconducting devices reduced circuit execution times by up to a factor of five (Physical Review Research 2024). Informationally complete measurement schemes parallelised algorithmic readout and reduced measurement overhead, while hardware-level optimisation exploited higher transmon states and connectivity-adapted circuit layouts. A joint study on exciton dynamics under strong dephasing linked Rydberg-based simulators to molecular energy-transfer processes (arXiv 2024). Collectively, these advances established MOQS as a leading demonstrator of hybrid quantum–classical workflows on existing quantum devices, supported by shared software, benchmark datasets, and joint publications ensuring methodological coherence and open-science compliance across the consortium.
