Laboratoire Interactions, Dynamiques et Lasers

New technologies of compact accelerators, in particular plasma accelerators, and laser-based x-ray sources, are on the verge of reaching maturity in this decade, making today the perfect time to steer them towards a broader scope of applications in academia, medicine and the industry. Training the next generation of entrepreneur-minded early-stage researchers on such a disruptive technology will enable them to start successful careers with significant societal impact. This is the goal we pursue with the Marie Skłodowska Curie Action Doctoral Network EPACE (European compact accelerators, their applications, and entrepreneurship). EPACE fosters a culture of excellence, innovation and critical thinking to help the next generation explore opportunities and guide it towards significant contributions in line with the EU missions. Emphasis is put on applications in industry (muon tomography), medicine (FLASH effect with particle beams from plasma accelerators), and impactful progress (reduced energy consumption of particle accelerators). An extensive curriculum from a world-class European business school will help the students identify and transfer the most promising innovations into commercial products. Coordinated by DESY, EPACE gathers 31 industrial and academic partners in Europe, to provide 15 PhD students with great scientific expertise, a thorough awareness of EU values and a drive towards entrepreneurship.

Research in the fields of nanoscience and nanotechnology is vital for sustainability globally: advancement in nanoscience and nanotechnology cannot be achieved without using research infrastructures (RI). RIANA encompasses 7 European networks of top-level RIs to cover the most advanced techniques relevant for synthesis, nanofabrication, processing, characterization, analytics, as well as simulation capacity. Highly customised and efficient access to 69 infrastructures is coordinated via a single-entry point and enabled through comprehensive Science and Innovation Service by senior scientists, experts for the transfer of technology from academia to industry, and highly trained Junior Scientists. The Junior Scientist boost RI experience to an entirely new level: they provide customised Science Service supporting users from initial ideas to hands-on experiments, data analysis and dissemination of results to generate the greatest impact from access to world-class RI. This core of RIANA is aligned to attract experienced and new users from academia or industry making their promising ideas a success and push them to higher TRL. RIANA is flexible to upcoming emergent scientific topics and needs: together with stakeholders from the nanocommunity, RIANA implements the opportunity to offer flexible access to additional infrastructures in, and even outside of Europe beyond the current consortium, and to direct the Science Service towards evolving user needs via additional specialised Junior Scientists. Based on the four years of experience, the RIANA consortium will develop a roadmap for the future of the nanoscience and nanotechnology at European RIs.

Lasers4EU is incorporating the major laser research infrastructures, in a large number of European member states, into a comprehensive virtual distributed laser research infrastructure that is offering to a broad user community, from academia and industry, access to an exceptional portfolio of technical and scientific capabilities. This unique set of instruments together with the specific scientific expertise at the host facilities allows Lasers4EU users to carry out high-level research in an extremely wide range of high-impact topics in life sciences, materials nano-processing, etc. Laser technology has experienced remarkable advances and breakthroughs and is now a key innovation driver for highly diversified societal applications and products, thereby substantially contributing to economic growth and to solving challenges in the areas of health, environment and energy. Through its strategic approach, Lasers4EU aims to strengthen Europe’s leading position and competitiveness. It facilitates long-term coordination of the laser research activities within the European Research Area and provides concerted and efficient services to scientific, industrial and medical researchers. The main objectives of Lasers4EU are to: • provide coordinated access to high-quality services based on a coherent and comprehensive consortium of 27 leading European laser installations offering to users from academia as well as from industry cutting-edge performances at the forefront of the laser technologies, • structure the European landscape of laser Research Infrastructure through enhanced access, extended geographical coverage, novel science diplomacy activities, improved synergies with other European networks and projects, • increase European human resources in the field of laser science by implementing training activities towards researchers from new domains of science and technology and from geographical regions where laser communities are still less developed.

Understanding the interaction between electromagnetic radiation and matter is crucial for unravelling the internal structure and processes of materials. Electromagnetic waves exhibit both wave-like and particle-like behaviour, with the quantized nature of light becoming apparent in the realm of quantum technologies. The QU-ATTO network aims to merge the fields of quantum optics and quantum information science with attosecond physics. This involves focusing on experimental campaigns to highlight quantum aspects in the interaction of intense laser fields with matter and advancing theoretical descriptions for a comprehensive understanding of the quantum state of light associated with intense laser fields. Traditionally, attosecond pulses have been generated using table-top femtosecond lasers. However, recent experiments performed at free-electron lasers (FELs) have demonstrated the production of isolated attosecond pulses and precise control of attosecond waveforms for pulse trains, leading to remarkable advancements in attosecond science. The network also aims to leverage recent advances in seeded FELs and high-intensity high-harmonic generation (HHG)-based attosecond sources to demonstrate the coherent control of electronic dynamics in systems of increasing complexity. The QU-ATTO network represents a comprehensive effort to advance the understanding and control of the interaction between electromagnetic radiation and matter, with a specific focus on merging quantum optics, quantum information science, attosecond physics, and free-electron laser science. The doctoral candidates (DCs) in the network will receive multifaceted scientific training encompassing experimental and theoretical aspects of quantum information science, strong-field physics, and soft X-ray and X-ray science, as well as extensive training in transferable skills and self-management techniques.

La physique attoseconde est à la pointe de la spectroscopie résolue en temps. En effet, elle exploite les impulsions lumineuses les plus courtes pouvant être produites expérimentalement pour sonder la matière, grâce au processus de génération d’harmoniques d’ordre élevé (HHG). Malgré l'immense succès de la science attoseconde, célébré par le prix Nobel de physique 2023, il n'y a toujours pas de consensus sur une description quantique de la HHG. ASAP propose plusieurs schémas expérimentaux pour résoudre ce problème et exploiter les caractéristiques quantiques de l'émission produite par HHG afin de jeter un nouvel éclairage sur le processus de photoionisation. L'exploitation de la nature quantique de la lumière a déjà permis d'augmenter la précision des détecteurs d'ondes gravitationnelles pour mesurer les distances. Le projet ASAP soutient que la maîtrise des propriétés quantiques des impulsions attosecondes produites par la HHG permettra d'améliorer la précision du chronométrage des événements les plus rapides qui se produisent dans la matière, et ouvrira de riches questions sur la notion de temps en mécanique quantique.

The recent development of broadband coherent extreme ultraviolet sources makes it possible to measure dynamics with attosecond resolution (1 attosecond = 10-18 s). This time scale is associated with the electron dynamics and more particularly to the electronic correlation in various systems, from atoms and molecules to solids. Generating and controlling processes on this time scale then gives the opportunity to develop new promising applications in chemistry and biology that can have high impact in society. TD-PICO-MF aims at studying electronic correlation through the measurement of the photoemission delay of core-orbital electrons in a laser-controlled molecular system. For this purpose, TD-PICO-MF brings together advanced technologies from the attosecond interferometry field and laser-induced alignment field, in order to resolve both spatially and temporally the photoemission process. In particular, the research project proposes to study, as a prototype, the photoemission from the 4d core-orbitals of the iodine atom in iodine monochloride (ICl) molecules in gas phase. The measurements will be realized during different laser controlled configurations of the molecular system e.g., during its alignment, orientation and dissociation. The expected impact is to gain a global picture of the influence of the molecular cationic potential during a chemical reaction and to evidence the role of electronic correlation through the measurement of 3D-scattering phase maps in the molecular frame. TD-PICO-MF will utilize existing, and forge new, international collaborations between experiment, theory and academia in order to tackle this complex problematic. The results of our work will be made globally available and presented to the general public. The post doctoral fellow will bring to the host his expertise on laser control of molecular systems and will be trained to the attosecond science and technologies, enlarging his scientific experience and employability.

La simulation quantique est l'une des technologies quantiques les plus avancées. Parmi les montages développés au cours des dernières années, les réseaux d'atomes de Rydberg sont l'une des plateformes les plus (sinon la plus) avancées. Les systèmes basés sur le réseau d'atomes alcalins de Rydberg peuvent émuler un hamiltonien de spin arbitraire avec jusqu'à 200 particules, bien au-delà des capacités d'un ordinateur classique. Cependant, la durée de la simulation est actuellement limitée à quelques microsecondes par la durée de vie des états de Rydberg de faible moment cinétique accessibles par laser. Le passage à des états de Rydberg circulaires, qui ont une durée de vie beaucoup plus longue, permettrait de dépasser cette limite. Cependant, les atomes circulaires alcalins sont difficiles à manipuler avec la lumière optique. L'objectif à long terme du projet SCiRQ est de développer un simulateur quantique basé sur des états circulaires du strontium. Les états de Rydberg des éléments alcalino-terreux ont un cœur ionique optiquement actif qui peut être utilisé pour manipuler l'atome. Le système proposé offrira de nombreux avantages par rapport aux plates-formes existantes utilisant des alcalins. Le deuxième électron de valence permet de piéger un atome avec un simple faisceau gaussien en utilisant la polarisabilité du cœur ionique. La diffusion de photons sur la transition du cœur va permettre de détecter les atomes de Rydberg en détectant leur fluorescence sur une caméra, alors que, dans la plupart des simulateurs, les états de Rydberg sont détectés comme une perte d'atome qui conduit à l’absence de signal sur l'image finale. Le deuxième électron fournira également un moyen de refroidir le mouvement de l'atome circulaire de Rydberg, limitant le chauffage du réseau survenant pendant la simulation. Le couplage électrostatique résiduel entre les deux électrons de valence peut aussi être utilisé pour manipuler l'état de l'électron de Rydberg à l'aide d'une lumière laser interagissant avec le cœur ionique, afin d’effectuer des opérations locales sur un site donné du réseau avec une résolution spatiale micrométrique. Le couplage entre les deux électrons, combiné aux techniques développées pour les expériences de piège à ions, ouvre également la voie à l'encodage de l'état de l'atome de Rydberg dans l'un des états métastables du cœur afin que la fluorescence de l’atome permette de mesurer l'état de Rydberg circulaire. Dans le cadre du projet SCiRQ, les deux partenaires LKB et LIDYL associeront l'expertise expérimentale du LKB à la connaissance théorique approfondie des atomes à deux électrons du LIDYL afin de préparer un réseau d'atomes de Rydberg circulaires de strontium piégés. Au cours des quatre prochaines années, nous voulons démontrer quatre fonctionnalités clés (piégeage, refroidissement, adressage individuel, détection) qui montreront le potentiel de cet atome pour la simulation quantique. Chaque pince piègera un électron de Rydberg dans un état circulaire avec en son centre un ion Sr+, auquel il sera couplé par interaction électrostatique. Le simulateur bénéficiera à la fois de la flexibilité des atomes de Rydberg et de la richesse des techniques des ions, fusionnant en un seul système les avantages de deux des plateformes les plus avancées qui existent aujourd'hui. Le projet aura également un impact au-delà de la collaboration LKB-LIDYL. L'expertise développée pour la préparation des états circulaires du strontium bénéficiera à de nombreux domaines de la technologie quantique. Le couplage de l'électron de Rydberg au cœur ionique permet d'utiliser la transition d'horloge de l'ion Sr+ comme mémoire quantique pour stocker l'état du qubit de Rydberg. Cela ouvre également la voie à l'utilisation d'atomes de Rydberg circulaires pour la conversion cohérente de photons micro-ondes en photons optiques. Les adaptations à température ambiante de l'expérience offrent des perspectives intéressantes pour la métrologie quantique.

Quantum Electrodynamics (QED) is the theory that unifies electromagnetism and quantum mechanics to describe how light and charged particles interact. Considered as one of the most accurately tested theories, it led Richard Feynman to call it “the jewel of physics”. Yet, in its strong-field (SF) regime, when the light fields E are ultra-intense and close to the so-called Schwinger limit (ES>10^18V/m) in the charged particles rest frame, QED has so far remained ‘terra incognita’ in experiments and the developed SF-QED theory has never received an accurate experimental validation. When the electric field is well above the Schwinger limit (E>1600 ES) in the particles rest frame, QED enters the so-called ‘fully non-perturbative regime’ (NP), for which there is currently no accepted theory to describe how light interact with charged particles. Due to the extreme fields values required, the SF and NP regimes of QED are out of the reach of all experiments envisaged so far with current high-power laser technology, that currently offers the most intense source of electric field on earth. To break this barrier, we propose a new approach based on so-called Doppler-boosted lasers, than rely on plasma optical devices dubbed 'plasma mirrors' to considerably boost the intensity of current lasers by orders of magnitude. By colliding such Doppler-boosted lasers with relativistic electron beams produced by laser-plasma accelerators, it could in principle be possible to reach the fully NP regime of QED. The implementation of such experiment is very ambitious, requires many complementary expertise (strong-field quantum electrodynamics, Doppler-boosting with plasma mirrors, high-intensity laser-matter modelling, laser-plasma acceleration and electron beam manipulation, laser and electron beam spatio-temporal characterization) and considerable funding. In this context, we plan to apply for an ERC synergy grant for the upcoming call. We recently set-up an international consortium of three principal investigators and are in the phase of writing the proposal. The present ANR project would help us support our consortium (on-site meetings and brainstorming) as well as finalizing the writing of our proposal (external ERC expert consultant).

EuPRAXIA is a distributed, compact and innovative accelerator facility based on plasma technology. It has been selected for the 2021 Update of the ESFRI Roadmap. In its first phase, its consortium of 51 institutes and industry partners will construct an electron-beam-driven plasma accelerator in the metropolitan area of Rome, thus bringing innovation, potential for spin-off companies, state-of-the art scientific applications and a vibrant international user community to the middle of Italy. In its second phase, EuPRAXIA will build one laser-driven plasma accelerator at a site to be chosen between several options in Europe. EuPRAXIA will serve users in ultra-fast science, e.g. on high-resolution medical imaging, deeply penetrating positron annihilation spectroscopy for materials and with Europe’s most southern free-electron laser (FEL). It will offer fascinating capabilities for research on biomolecules, viruses and microscopic processes. EuPRAXIA will thus be a transformative step in the development of ultra-compact accelerators and applications. The Preparatory Phase project EuPRAXIA-PP will prepare its full implementation.