Periodic Reporting for period 2 - PASQuanS (Programmable Atomic Large-Scale Quantum Simulation) Reporting period: 2020-04-01 to 2022-03-31 Summary of the context and overall objectives of the project PASQuanS aims at performing a transformative step for quantum simulation towards programmable analogue simulators, addressing questions in fundamental science, materials development, quantum chemistry and real-world problems of importance in industry. PASQuanS builds on the achievements of the most advanced quantum simulation platforms, based on neutral atoms in optical lattices or arrays of optical tweezers, interacting via collisional or Rydberg-state-mediated interactions, and trapped ions.By scaling up these platforms towards several hundreds of atoms/ions, by improving control methods and making these simulators fully programmable, PASQuanS will push these platforms far beyond both the state-of-the-art and the reach of classical computation. Full programmability will make it possible to address quantum annealing or optimization problems much sooner than digital quantum computation. PASQuanS will demonstrate a quantum advantage for non-trivial problems, paving the way towards practical and industrial applications. PASQuanS unites five experimental groups with complementary methods to achieve the technological goals, connected with five theoretical teams focusing on certification, control techniques and applications of the programmable platforms, and five industrial partners in charge of the key developments of enabling technologies and possible commercial spin-offs of the project. PASQuanS will result in modular building blocks for a future generation of quantum simulators. Possible end-users of these simulators, major industrial actors, are associated with the consortium. They are engaged in a dialogue on quantum simulation, and help to identify and implement key applications where quantum simulation provides a competitive advantage. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far During the whole project, the PASQuanS partners have worked in five interconnected directions, which were the five main objectives of the consortium.1. We have developed, in collaboration with the industrial partners, the next generation of underpinning technologies that will be used to build scalable and programmable quantum simulators, with a medium-term goal within the 10-year Flagship of reaching over 1000 interacting atoms in industry-ready platforms. We have set the foundation for this by: • merging cryogenic techniques with standard atomic and optical physics techniques for an improved shielding from noise and relaxation processes, • enhancing the level of control of atomic-physics-based platforms using the latest technological developments from industrial partners (laser stabilization in phase and intensity, higher power, and flexibility of optical potentials), enabling systems integration and miniaturisation, • scaling up the number of atoms/ions, while enhancing the level of control on each, with now particle numbers above 50 (ions), 300 (tweezer array), and 1500 (optical lattices).2. We have developed the theoretical tools required to certify and benchmark quantum simulators. Some were demonstrated on existing platforms within the consortium: randomized unitary operations to measure energy variance or entanglement in small system size. 3. We have performed simulations with these systems beyond the reach of classical simulation. Quantum advantage has been reached on scientific problems involving dynamics of phase transitions and quantum transport in strongly interacting systems. This lays the ground for the platforms’ developments towards quantum advantage for real-world problems in a next phase.4. We have developed new control techniques and architectures to perform quantum simulation, making use of the programmability and enhanced control over our platforms. We have developed and tested hybrid variational quantum methods and assessed the potential of optimal control methods.5. In collaboration with key industrial end-user partners in Europe, (i) we have identified their demand in terms of quantum simulation, (ii) in return we have presented them the capabilities and opportunities brought by quantum simulation, and (iii) we have developed means to use our new quantum simulation platforms for “real-world” problems relevant to these end-users. Through a fruitful dialog with industry end-users, we have explored use-cases in quantum metrology, combinatorial optimization, machine learning, medical applications, in the finance industry, in solving partial differential equations, in big-data problems and in high energy physics. We have explored in-depth a specific application from EDF and its potential implementation on Rydberg quantum simulator.At the end of PASQuanS, we thus provide: (i) modular systems to be implemented as building blocks on experiments, (ii) a mapping of problems of interest to the industrial world onto our simulation platforms (Deliverable 5.1) and (iii) a roadmap for the next phase of the Flagship (Deliverable 5.2). These outcomes pave the way towards the transfer of the building blocks to industrial partners, for industry-driven production of quantum simulators expected in the next phase of the Flagship.Finally, the technological and conceptual developments carried out within PASQuanS led already to the filing of several patents and to the creation of three startup companies: (i) Pasqal (https://pasqal.io) (ii) ParityQC (Austria) (https://parityqc.com) which aims at developing platform and method agnostic quantum software solutions, and (iii) QRuise GmbH (Germany).Besides these scientific developments, PASQuanS was committed to dissemination, communication and outreach activities in many forms: participation to scientific conferences and schools, interviews in the media, press releases about scientific achievements or events. We maintain an active website (www.pasquans.eu) and Twitter account (@pasquans).Due to the Covid it was almost impossible to hire post-docs in RP2. In our case we therefore use the salaries to pay long period master students (1 year and 6 months respectively), hence the low salaries. 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) All of the developments obtained by the PASQuanS consortium, be they conceptual, experimental or technological, are beyond the state-of-the-art. They indicate that the platforms are now able to provide a practical quantum advantage. The dialog initiated with end-users has already led to the exploration of real-life and industrial use-cases based on a quantum simulation approach. These will pave the way towards the transfer of the building blocks to industrial partners, for industry-driven production of quantum simulators expected at the end of the Flagship.In addition, PASQuanS contributes to the strategic objectives of the Flagship and helps expanding the European leadership and excellence in quantum technologies. It is deeply involved in the training of a new generation of quantum engineers that will form the required highly skilled workforce in Europe in order to maintain and develop the leadership of Europe in the field of Quantum Technologies. Quantum Simulation Platforms in PASQuanS
