The core of the action is to pool in the unique expertise in theory and experiment within europe and the exceptional availability of several xfels, an impressive number of world class laboratories with hhg table-top sources of euv to soft x-ray attosecond and femtosecond pulses, and an exceptional pool of theoreticians.

Applications of non-linear spectroscopy in atomic and molecular science, condensed matter systems, chemistry and biology, will grant access to the ultrafast regime with temporal (as/fs), energy (meV) and momentum resolutions (fractions of nm-1) with unprecedented detectable flux and chemical specificity, enabling groundbreaking advances and becoming the foundation for the emergence of the next generation of scientists who will be users of cutting-edge experimental tools.The development of robust theory models will complement the experimental activities providing a strong benchmark to the experimental data and creating a fundamental link between theory and experimental results.

our focus

The focus of the NEXT Action is to create a network to develop new EUV/X-ray non linear schemes at HHG table-top and XFEL sources able to selectively detect charge, spin, lattice and orbital dynamics in molecules and condensed matter while having a robust theoretical understanding of the underlying processes. This challenge is well beyond the capability of a single laboratory and calls for a collective effort.

This challenge is well beyond the capability of a single laboratory and calls for a collective effort.

Main Challenges

Design of new experimental tools
to perform novel EUV/X-ray non linear spectroscopy experiments in order to enlarge the range of excitations that can be probed with element-sensitivity and nanometer/femtosecond resolutions.

Create and/or adapt current EUV/X-ray sources ensuring the best performance during the experiments. 

Investigate the applicability of these new methods at HHG table-top and XFEL sources on well established model systems.

Application of these techniques to relevant samples in condensed matter: a) Ultrafast demagnetization dynamics; b) Detection and manipulation of charge density waves; c) Thermal transport at the nanoscale; d) Cancellation of the active center of molecules in the bulk. 

Identify and consolidate the protocols to be followed to ensure successful implementation of EUV/X-ray NL methods to specific areas such as Atomic, Molecular and Optical (AMO) Physics, Materials Science and (Bio)chemistry.

Application of these techniques to relevant samples in AMO: a) Stimulated Raman to study and selectively populate electronic/vibrational levels in simple molecules; b) Study the flow of charge across a molecule with multiple functional groups; c) Resonantly-enhanced difference-frequency generation for selective core-excitation.

Develop and implement dedicated and efficient computational tools to describe the experimental data, taking into account the time evolution of electron-electron interactions, electron-phonon as well as spin and orbital couplings.

Application of these techniques to relevant chemical compounds: a) Accessing optically-dark states in transition metal compounds or complexes via stimulated RIXS: b) Investigate diffusion of photogenerated reactants at short range using hard X-ray to EUV TG spectroscopies. 

Develop an integrated theoretical framework for solving the many, conceptual no less than practical, problems that hinder the understanding of quantum dynamics at nano/femto scales, as well as to steer the experimental efforts and interpret the data.

Develop theoretical physical models of EUV/X-ray NL radiation-matter interaction 

Specific objectives :

    • Develop innovative experimental capabilities and consolidate early proof-of-principle demonstrations in the EUV/X-ray regimes. Several methods are common to all areas and call for a concerted effort. This also applies to theoretical formalisms and efficient codes able to interpret and support the experimental data.
    • Create a strong synergy between HHG table-top sources and XFELs across Europe ensuring the success of the Action by investigating experimentally benchmark systems to determine the applicability of nonlinear spectroscopy validating and verifying the experimental findings.
    • Provide protocols and best practices for the successful implementation of EUV/X-ray NL methods, from which the scientific community shall benefit and expand their research and innovation portfolio in a multidisciplinary approach.
    • Develop new physical models of EUV/X-ray nonlinear radiation-matter interaction, adapt Coordinate experimental and theoretical efforts in dedicated campaigns with a large number of international experts, bridging competencies through different cultural and scientific backgrounds.
    • Stimulate the coordination between the different scientific communities around Atomic-Molecular-Optical physics, Condensed-Matter and (bio)-chemical scientists to develop cutting-edge EUV/X-ray methodologies together by organizing networking events, the exchange of ideas in dedicated workshops and common participation in shared scientific campaigns.
    • Fostering knowledge exchange and the development of a joint research agenda around cutting-edge EUV/X-ray methodologies and XFEL sources, elaborating sustainability strategies.
    • Gather international experts with the technical knowhow and capabilities (XFELs and HHG science and instrumentation, laser experts) required to achieve the goals of this Action including groups in specific experimental and theoretical fields (atomic and molecular physics, condensed matter, chemistry) and with complementary competences.
    • Expand the scientific community of EUV/X-ray table-top and XFELs providing accessibility to infrastructures, instrumentation and tools, actively involving ITC (Inclusiveness Target Countries) members to overcome limitations in resources, funding and infrastructure through short term scientific missions.
    • Exchanges between experimental and theoretical groups and between groups with complementary expertises will be particularly encouraged to ensure that ECIs (Early Career Investigator) will be trained in several areas.
    • Exchange of knowledge and experience within and outside the participants of the Action including interdisciplinarity and equality through dedicated physical and electronic platforms.
    • Foster Young European Researchers to the next frontier of HHG table-top and XFELs cooperation.
    • Creation of a platform for equal opportunities for women researchers and inclusiveness for underrepresented minorities (UNESCO 2030 Agenda for Sustainable Development).
    • Promote Young Scientist responsible professional and personal growth through international research experience, to expand their view of the World and make them global citizens.