MOlecular Quantum Simulations

Project Information

MOQS

Grant agreement ID: 955479

DOI

10.3030/955479

Project closed

EC signature date 3 September 2020

Start date 1 November 2020

End date 30 April 2025

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 3 930 209,98

EU contribution

€ 3 930 209,98

Coordinated by

UNIVERSITE DE STRASBOURG
France

Periodic Reporting for period 2 - MOQS (MOlecular Quantum Simulations)

Reporting period: 2022-11-01 to 2025-04-30

Summary of the context and overall objectives of the project

Funded by the Marie Skłodowska-Curie Actions programme, the MOQS project aims to provide interdisciplinary and intersectoral training to 15 early-stage researchers in the emerging field of quantum computing of molecular structure and dynamics. The field sits at the crossroads of chemistry, solid-state and quantum optical physics, computer science and quantum information. It covers a large variety of possible industrial (e.g. catalysis-on-demand and drug design) as well as scientific (e.g. fully ab initio and complete quantum mechanical description of complex molecular reactions) applications. The consortium comprises eight academic partners, three non-academic beneficiaries and five organisations.
MOQS has four main scientific Research Objectives, each one developed in a separate Work Package:
• Development of optimal algorithms that exploit quantum resources to solve chemistry problems [WP1 - Quantum chemistry: From classical algorithms to quantum algorithms]
• Development of solid state superconducting qubit and atomic systems based on Rydberg states in terms of scalability and interaction control with aim to deliver quantum advantage [WP2 - Pushing the limits of quantum hardware]
• Development of computational methods that best exploit the unique capabilities of physical platforms, including noisy, lossy, limited resources of near-term quantum hardware [WP3 - Development of platform-optimized computational strategies]
• Quantum simulations of electronic structure and energy transfer dynamics of relevance to chemistry [WP4 - Demonstration of quantum simulations of chemical structures and dynamics]

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

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.

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)

ince the start of MOQS, research carried out by ESRs and documented in their doctoral theses has advanced significantly beyond the state of the art outlined in the original proposal. While the proposal identified the key challenge of moving from proof-of-principle demonstrations of quantum chemistry on small molecules to scalable simulations relevant to chemistry and materials science, the results now show concrete progress in this direction.

Algorithmic progress has been substantial. Several theses developed and benchmarked advanced hybrid quantum–classical approaches (e.g. VQE variants, qEOM, QCNNs) tailored to noisy near-term devices. These methods extend applicability from small molecules to strongly correlated models such as the Fermi–Hubbard Hamiltonian, providing error-resilient strategies, reduced circuit depth, and improved ansatz design beyond the original objectives.

Hardware developments have also exceeded expectations. ESRs realized optimized multi-qubit gates for neutral-atom and superconducting qubit platforms, compact optical waveform modulators, and novel stroboscopic imaging protocols for atom arrays. These results directly address the project’s aim to “push the limits of hardware,” now demonstrating robust, higher-fidelity operations that enable more complex simulations than initially envisaged.

Applications in physics and chemistry go well beyond the “beyond period I molecules” target in Annex 1. ESR work expanded to simulating energy transfer processes, non-local effects in spin chains, and strongly correlated bosonic and fermionic systems. Several theses even propose technological applications not foreseen in the initial plan, including quantum batteries and quantum-enhanced spectroscopy.

Taken together, these achievements show that MOQS is no longer only preparing the ground for future demonstrations. The project is already delivering proof-of-principle advances in both algorithms and hardware, moving substantially closer to the goal of demonstrating quantum advantage in molecular problems, and establishing pathways toward industrial and societal applications.

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