Information technologies are at the cusp of another revolution triggered by the emergence of new generation of wireless telecommunication technologies and the promise of new paradigms through the quantum computer. This development requires the introduction of new materials for post CMOS technologies that offer new ultra low dissipation microwave functionalities, while remaining compatible with integration and nano-patterning. In this respect, magnetic garnets with a well-established track record of improving the performance of microwave or optical devices are prime candidates. HARMONY will demonstrate this by proof of principle in the form of an integrated analog coherent microwave converter between photon-magnon-phonon. So far the development of yttrium iron garnet (YIG) thin films for integrated solutions was hampered by the fact that high quality epitaxial growth could only be achieved on gadolinium gallium garnet (GGG) substrates. GGG, however, must be considered a matched material for both the phonon and photon character, which thus offers an energy leakage path and as a consequence prohibits the confinement of their microwave energy within the sole YIG layer. To overcome this problem, a new process developed by the group of G. Schmidt in Halle has allowed to fabricate free standing micron-size YIG beams with high magnon life time, hereby mainly avoiding the energy leakage through the substrate. These new objects have the potential to become game-changers for high-fidelity front-end telecom components operating at GHz frequencies. Furthermore, they can provide new tools for quantum information exchange between distant qbits also operating at GHz frequencies. HARMONY will initiate a technological breakthrough by providing a viable development path for integrating the coherent and efficient interconversion of information between photon-magnon-phonon on a chip. It builds on the tripartite hybridization process inside magnetic garnets that employs nested resonances of increasing finesse. HARMONY focuses on the fabrication of suspended YIG beams to remove technological road-blocks by the following goals: i) provide an efficient scheme to excite GHz phonons by magneto-elastic effects through the co-tuning of 3 cavities; ii) improve the energy efficiency with an ultra-low loss material that is isolated from the substrate for the highest finesse and iii) implement this in an integrated on-chip device. The objective of the project HARMONY will be to evaluate within a 3 years period, how these suspended garnet structures perform as microwave transducers. The project is designed as a collaboration between the group of Spintec, Néel and Halle. The synergy of their complementary track records will allow us to realize these ambitious goals. While coupling of magnons to microwave photons at low temperature will mainly be performed in Germany, the coupling of magnons to phonons will be performed in France. The micropatterning and YIG deposition is uniquely located in Halle while micromagnetic simulations and resonator design as well as characterization of all structures by FMR microscopy at room temperature is done at Spintec, matched by opto-mechanical surveys of the vibration pattern at Néel. The envisioned sequel of the HARMONY project is to extend the concept of coherent coupling to entanglement with whispering gallery optical modes.

FLUOLUV is a 48-months PRC involving three national academic research groups [IRCP, SIMAP, NEEL] and one Japanese team [IMS] that will participate to the project from own resources. All will put together their complementary skills in the field of materials and optics to develop nonlinear optical (NLO) crystals for an efficient UV conversion. The generation of UV light by means of NLO processes from an infrared fundamental beam is indeed the desired path to design all solid-state, compact and reliable UV lasers. However, there are only very few commercial NLO crystals that can achieve the last stage of frequency conversion towards UV despite the big market of UV lasers. For this purpose, the consortium will develop new alkaline-earth fluoroborate NLO crystals aimed to solve some limitations of current NLO crystals. IRCP group has already grown first single crystals from flux method and demonstrated their capability to generate 355 nm, despite a crystal quality to improve. Chemical substitution should extend and tune this range of capabilities deeper in UV to achieve for the first time laser generation at 266 nm by frequency doubling of 532 nm in an angle non-critical phase matching (NCPM) configuration. However, the demonstration of the full potentialities of these fluoroborate crystals requires a complete characterization and optimization of their properties. To boost the development of these nonlinear materials, the consortium set up a methodology consisting of a complementary multidisciplinary approach as follows: 1. Theoretical approach: Thermodynamic and ab-initio simulations. The thermodynamic properties of the solid/liquid phases and compounds as well as the gaseous species of the reciprocal fluoroborate family system will be modelled using the Calphad approach. In addition, DFT calculations will be used to calculate the energy of formation and the heat capacity of this family of materials as well as relevant physical properties. Theoretical data will be compared to experimental values. All generated results will be used to develop a coherent Gibbs energy dataset and calculate the relevant phase diagrams to define optimum crystal growth conditions: melt composition and temperature interval for growth by taking into account the gas atmosphere and volatilization effects. 2. Material approach: Preparation of fluoroborates single crystals. New flux growth compositions and conditions based on an original top-down approach fed by theoretical calculations will be tested to improve the fluoroborate family crystal quality. The target is to provide high-quality crystals and oriented samples of 10 to 20 mm length for laser frequency conversion tests. The composition tuning of the materials will be investigated to generate 266 nm laser wavelength by frequency doubling in NCPM conditions for the first time. 3. Nonlinear optical properties investigations: The dielectric frame orientation and the optical properties will be determined with special care about their temperature dependance. Direct measurements of phase-matching directions and the associated conversion efficiencies, angular and spectral acceptances will be performed using the sphere method. We will focus on UV generation at 355 and 266 nm by quadratic processes from 1064 nm fundamental laser wavelength to provide reliable dispersion equations of the principal refractive indices as well as the magnitudes and relative signs of all the nonlinear coefficients. This corpus of data will enable the calculation of the best orientations of the fluoroborate crystals for optimized configurations of different UV generators. 4. UV frequency conversion efficiencies. The optical damage threshold and effects limiting the UV nonlinear conversion will be estimated. The practical applications of these NLO fluoroborates will be demonstrated by developing long-term UV emitting prototypes using sub-ns high peak power microchip laser based on 1064 nm-Nd:YAG.

Superconductivity is a fascinating quantum state of condensed matter. Its study and understanding have always aroused immense interest in fundamental physics, but also in materials science and its exploitation leads to numerous technological applications: lossless current transport, energy storage, quantum computation or sensors with unprecedented resolution. In 1986, the discovery of high Tc superconductivity in cuprates allowed the acceleration of enormous progress, both experimentally and theoretically, in several areas of condensed matter physics. However, the origin of high Tc superconductivity is still an unresolved problem; One of the main reasons is the complexity of the physics of cuprates resulting from multiple interactions in competitions (magnetic fluctuations, strong electronic correlations, charge-network coupling, etc.) and nearby orders (charge density wave, antiferromagnetism, pseudo-gap, etc.). The emergence of superconductivity in nickelates, structural and electronic “cousins” of cuprates, was eagerly awaited, but only postponed in 2018 in LaNiO3 / (La, Sr) MnO3 superlattices and in August 2019 in thin layers of the “Infinite phase” Nd0.8Sr0.2NiO2 / SrTiO3, due to the inherently complex chemical processes to stabilize this phase. The SUPERNICKEL project will explore the chemical, structural, physical and electronic properties of new superconducting nickelates, using a transversal approach involving the synthesis of thin films, superlattices and massive materials, the crystallochemistry of the solid, a large battery of macroscopic probes. and experimental microscopic (magneto-transport, X-ray diffraction, photoemission spectroscopy, among others) and theory. Our objectives are to determine the nature and symmetries of the superconducting state, the origin of the interaction forming Cooper pairs, by clarifying the similarities and differences between nickelates and cuprates. Over the past few months, we have focused our efforts on mastering the complex protocol allowing to stabilize the phase of infinite layers and to synthesize the superconducting nickelate.We have already obtained samples with good nominal compositions and close to superconducting instability, and we are confident that very soon, after optimizing their synthesis, we will be one of the few groups in the world to have good quality superconducting nickelates. . In parallel, we will work on other nickelate phases. The possibility of synthesizing and studying in depth, in addition to thin films and superlattices, bulk nickelates will also be a unique approach of SUPERNICKEL. We expect from the thin film / solid material comparison essential and potentially unique information on the specificity of the thin film / substrate form in the emergence of superconductivity. Our multi-approach strategy integrates design, development, detailed crystallochemical characterization, exploration of the physical and electronic properties of normal and superconducting states and theoretical modeling. The SUPERNICKEL consortium thus covers a wide range of know-how in all the essential fields and techniques necessary to tackle this problem: oxide chemistry for the synthesis of massive and thin layers, crystallography, strong correlations, magneto-transport, structure. electronics, magnetism and superconductivity. We also hope that beyond the SUPERNICKEL consortium, the dynamics of this project will become a strong pillar to consolidate and revitalize the French community working in the wider field of new superconductors.

The ACTION project aims to explore and develop a new breed of transistors using an ultra-wide bandgap AlGaN channel. This PRCE project is made up of three academic laboratories, CRHEA, IEMN and the Néel Institute, and the startup EasyGaN as the industrial partner. These AlGaN transistors will make it possible to lay the foundations for a future generation of power components that will offer higher operation voltage and temperature stability beyond the limits of GaN. The targeted performances will compete with contemporary SiC-based transistors. Thanks to the increased efficiency at high voltage operation (1200V), currently inaccessible to GaN-on-Silicon transistors, these components will reduce the losses that occur during the multiple transformations of electrical energy from its production to our daily use. The key point of the project is the development by molecular beam epitaxy (MBE) of AlGaN/AlGaN heterostructures on large diameter silicon substrates. These novel and CMOS compatible semiconductors will strengthen the current efforts of the main French players in the field. In the context of decarbonization and therefore a massive electrification, the ACTION project will play an important and strategic role in the creation of a new generation of semiconductor components improving energy management. This project is based on remarkable preliminary results since a breakdown field greater than 2.5 MV/cm has already been measured on extremely simple AlGaN channel HEMT structures. This breakdown field value is already beyond the state of the art of GaN-on-silicon HEMTs, which is typically around 1.5 MV/cm. These promising results confirm the interest of this approach, especially since these extremely simple structures (without strain engineering or defect density reduction) have been epitaxially grown on a silicon substrate. The ACTION project aims to develop AlGaN channel HEMT structures optimized in terms of defects and strain engineering on large diameter silicon substrates based on the unique CRHEA know-how of more than 20 years of MBE epitaxy. Part of this know-how has been already transferred to the startup EasyGaN. In particular, a patent which makes it possible to reduce the density of dislocations in the AlGaN alloy has been licensed to EasyGaN. Another key point of the ACTION project is the optimization of the different processing steps and the realization of the device. The team of Farid Medjdoub (IEMN) is at the state of the art in this field. Their expertise will make it possible to optimize the performance of the structures grown in the project. Julien Pernot's team (Institut Néel), recognized as a leader in the field of ultra-wide-gap materials, will provide an in-depth study of the properties of the AlGaN. In particular, the team will provide expertise on the electron transport properties which are the core of the project. All things considered, the ACTION project will enable EasyGaN to add a high value and strategic product to its catalogue. The partnership offers perfect complementarity by bringing unique know-how to carry out this ambitious project aimed at innovative power components. The project will also benefit from the expertise of external partners such as: - the company Knowmade specialized in patent analysis and consulting in technology watch and intellectual property strategy, - the University of Padua for dynamic measurements, - the University of Bristol for thermal analyzes and, - the SME Riber for developments and technical support around MBE growth on 8" substrates.

Bioaccumulation of mercury from the bottom to the top of the food chain is a worldwide concern for ecosystem health and human food supply. Associations of Hg with natural organic matter (NOM), especially with reduced sulfur, to a great extent determine the bioavailability and toxicity of this hazardous element in the biosphere. There is, however, a huge unmet need for improved understanding of (1) how Hg is bound at the molecular-scale in NOM, (2) how its bonding environment influences its solubility, hence its mobility and subsequent uptake into the food chain, and (3) how it is bioaccumulated and detoxified in biological tissues such as fish (e.g., brain, liver, kidney, muscles) and hairs of human beings (medulla, cortex and cuticule). These fundamental questions are crucial to mitigate the impact of Hg on the biosphere. In this proposal, experiments relevant to natural processes and direct measurements on Hg-affected animals and humans are designed to examine (1) relationships between the speciation of Hg in dissolved organic matter (DOM) and its bioaccumulation and detoxification in the tissues of fish, taking Danio rerio (zebrafish) as the model animal in the laboratory, (2) the compartmentation of Hg among tissues down to cell organelles in D. rerio, in insectivorous fishes and fish eaters from French Guiana, and among the three major identifiable tissular regions of the hairs of contaminated Wayana and Wayampis Amerindians, and (3) the sequestration forms of Hg in all these tissues. The research is driven by six hypotheses, which will be tested by an interdisciplinary and international team of researchers : a) Hg is dominantly speciated as HgxSy clusters in DOM at concentrations relevant to realistic environmental processes, and their amounts depend on the concentration of cysteine-like thiolated sulphur groups. b) DOM-associated Hg modulates mercury and methylmercury transfer in the water column and in fine the overall bioavailability of this element. c) The detoxification form(s) of Hg differ, to an extent to be determined, (1) among organisms and tissues, in particular between the brain, liver, and muscles of fish; selenium may precipitate mercury in some tissues, as observed in mammals, and (2) through the food web from vegetarian/insectivorous to predatory fishes to humans. d) Hg-thiolate clusters in metalloproteins produced by cells to detoxify Hg are analogous to the HgxSy clusters in DOM. e) The expression of the mt1 and mt2 genes, which encode the two metallothionein isoforms MT-I and MT-II in D. rerio, is influenced by the speciation of Hg. f) The nature of the HgxSy clusters in DOM influences mercury ecotoxicity and modulates such outcomes as adaptive genetic response, mitochondrial impairment, swimming behaviour, and genotoxicity in zebrafish, and genotoxicity in S. subspicatus. Beyond the discovery of fundamental processes that control the bioavailability and toxicity of this global environmental contaminant and the mere production of high-quality scientific articles of wide interest to a large community of scientists and to media, the broader societal benefit of this proposal is to dissociate, for the first time, speciation and concentration in the evaluation of the bioaccumulation and toxicity of Hg. This knowledge is essential to improve the reliability and significance of assays for assessing mercury toxicity by taking into account the real form of Hg in the environment. So far, acute toxicity tests are performed with free ionic or small molecular Hg species, which are not relevant to natural conditions.