The research field of ultracold (T<<1mK) molecules involves an increasing number of groups throughout the world, due to their foreseen applications in quantum technologies and cold chemistry. Molecules at ultracold temperatures can be precisely controlled in both their translational motion and their internal quantum states. Unfortunately, until recently, laser cooling could not be applied easily to molecules because they generally do not possess suitable closed optical transitions, like in atomic systems: their complex internal structure, prevents them from transferring cooling and slowing methods known from atomic physics, except for a very restricted class of molecular species . The main goal of the current proposal is to refine laser cooling further, to invent new cooling schemes which take into account the unique features of molecular structure, and produce a dense sample of absolute ground state of cold trapped Rb2 molecules. We intend to study bi-molecular collisions in two directions: first by finding optimal conditions to suppress them by optical shielding, and second to observe molecule-molecule collisions, possibly assisted by light, eventually forming Rb4 polyatomic molecules. The proposal is built upon three main objectives mixing experimental and theoretical aspects: (i) The experimental achievement of laser-cooling and trapping of Rb2 molecules from a supersonic molecular beam, guided by simulations elaborated using molecular structure calculations. For this aim, we will implement a rovibrational optical pumping technique, which will act like a broad-band repumping light source, thus imposing a “closed optical transition” to the molecules. (ii) The investigation of suppression of bi-molecular collisions using optical laser light which is blue-detuned from a suitable electronic molecular transition. Increasing the shielding efficiency will be of great interest for experimentalists whose aim is to obtain high density long-lived samples of ultracold molecules, paving the way to quantum degeneracy. (iii) The search for ultracold inelastic and reactive collisions between Rb2 molecules, possibly assisted by light, including photoassociation and formation of stable Rb4 molecules. Photoionization mass spectroscopy will allow us to identify the species present in the sample (Rb, Rb2, Rb3 , Rb4). Such processes exemplify a novel ultracold chemistry, intuitively assumed to be dominated by the long-range interactions between the reacting particles, but possibly with a complex interplay with short-range dynamics. This is still an open question, since the large amount of resonances of the collisional complex may give rise to a long-lived complex at short distances. The detection of photoassociation lines may provide an experimental insight into the role of these resonances in the dynamics. This work is a continuation of a successful long collaboration between the Brazilian USP-SC experimental group and the French LAC theoretical team. Together they have made a series of achievements including the successful creation of ultracold ground state rubidium diatomic molecules by short range photoassociation. Four joint scientific papers have been published within this collaboration since 2013.

The cold Rydberg atoms are today recognized as a powerful tool for studying many physical situations, combining extreme and exaggerated properties of cold atoms and Rydberg atoms, respectively. Indeed, the electric dipole momenta of the Rydberg atoms can reach values several thousands times those of very polar molecules! Cold Rydberg excitation offers the possibility to entangle physical systems at large distances with many applications for quantum engineering and quantum simulation. The aim of the proposal COCORYM, for COrrelated COld RYdberg Matter, is to study the preparation, the evolution and the control of a cold Rydberg gas in configurations of very long-range interatomic dipole-dipole interactions, which can in a first approximation considered as a frozen gas, the properties of which can present similarities with an amorphous solid. Such atomic ensembles simulate mesoscopic situations at the crossings of condensed matter physics, plasma physics and chemistry, which will be investigated for characterizing properties of coherence of the matter. The proposal COCORYM will illustrate through five ambitious objectives, the different properties of coherence of Rydberg ensembles: (i) the characterization of a few-body in a cold Rydberg gas; (ii) the demonstration of superradiance for an ensemble of entangled pairs of Rydberg atoms; (iii) the Rydberg photoassociation for the formation of macrodimers, constituted by two bounded Rydberg atom; (iv) the quantum or classical diffusion of the Rydberg excitation; (v) the auto-organisation of laser cooled and trapped Rydberg atoms. The three first objectives will be tackled with the beginning of the proposal, using an available setup with Caesium atom. These results will constitute important steps in the understanding of the behavior of an ensemble of Rydberg atoms in strong long-range interaction. They will be real breakthroughs to open further developments of the entanglement of an ensemble of atoms, the control of cooperative emission or absorption, and an ultracold chemistry at mesoscopic distance. The two next objectives concern the properties of correlations and collective many-body effects; they necessitate the development of a new experimental setup, the tasks of which are planned during the first two years of the proposal. The prepared Rydberg ensembles correspond a priori to a disordered medium, but ordered or partially ordered situations can be prepared in one-, two- or three-dimensional space. The use of the dipole blockade of the Rydberg excitation is a way to prepare a correlated ensemble of excited atoms. The created correlations between the atoms are difficult to fully characterize. We need for that to develop a selective, temporally and spatially resolved detection for the Rydberg atoms. To go further, we need also to be able to laser-manipulate cold Rydberg atoms. A purpose of the proposal is to prepare an ensemble of strongly interacting and laser-controllable cold Rydberg Ytterbium atoms. The new Ytterbium setup is an important investment for the future of the cold Rydberg atom subject at the Laboratoire Aimé Cotton. The Ytterbium possesses two optically active electrons. Laser-cooling and Bose-Einstein condensation can be reached. Rydberg Ytterbium atoms can also be doubly-excited by using the second valence electron to perform a non-destructive imaging detection and to manipulate, cool or trap the Rydberg atoms, for controlling the cold Rydberg assembly. A complication of the experiment is the autoionization process of the doubly excited Rydberg atoms. To prevent the autoionization of the doubly excited atoms, an important task will be to initially prepare the Rydberg atoms in a high angular momentum state, which is non autoionizing and also possesses a long radiative lifetime.

The ENVIE-FIB proposal aims at exploiting the unique physical properties of NV color centres in ultrapure single-crystal CVD-grown diamond to develop innovative quantum-based devices with unprecedented performances, especially an efficient single-photon source. The consortium gathers the group of Jean-Francois Roch and Vincent Jacques in Laboratoire Aime Cotton, experts in the physics and the applications of NV centers, with Orsay Physics. ENVIE-FIB will build a combined instrument based on the i-FIB ion column developed by Orsay Physics and which is based on a ECR gas source adapted to xenon and nitrogen molecules. Nitrogen will be used to create NV centers by shallow ion implantation, with the goal to achieve 10-nm resolution in the positioning of the NV center. Xenon will be used to mill the diamond layer, in order to overcome the limitation due to the high index of refraction of diamond. We will elaborate a solid immersion lens (SIL) above the NV center which will lead to an enhancement of the excitation and detection of the coupled single NV centers by approximately one order of magnitude. The ion column will be associated to on-line optical microscope which will give an in situ image of the implantation area. The chamber will be designated to integrate a scanning electron microscope which will provide a live observation of the milling process. The electron image could also allow the implantation of nitrogen in photonics nanostructures associated to high-efficiency single-photon sources, such as photonic crystals and micropillars. In conclusion, ENVIE-FIB aims at integrating the efforts of the the two partners in order to develop a technology for the controlled fabrication of NV centers and their coupling to microstructures. The instrument delivered in the project will push further the limits of the promising NV-based technologies.

EDMs, i.e. electric dipole moments of electrons, neutrons or nuclei are sensitive probes for new physics beyond the Standard Model of particle physics. In the present project, we propose to measure the EDM of those systems embedded in a cryogenic solid matrix of inert gas or hydrogen. Matrices offer unprecedented sample sizes while maintaining characteristics of an atomic physics experiment, such as the possibility of manipulation by lasers. An EDM experiment on molecules in inert gas matrices has the potential to reach a statistical sensitivity of the order of 1e–36 e cm; a value beyond that of any other proposed technique. With this project, in a strong collaboration between experimental (LAC, ISMO,LPL) and theoretical (CIMAP) groups, we first aim at performing a detailed investigation of all limiting effects (mainly the ones limiting the optical pumping performance and coherence time) using Cs atoms. This should provide a first proof of principle EDM measurement and set the ground for precise study of systematic effects which will allow EDMMA to reach unprecedented precision

The main objective of DIAMESTAR project is to evaluate the efficacy of a new small interfering RNA(siRNA)/nanocarrier complex to treat Ewing sarcoma (ES) metastatic tumor xenografted on mice, when this nanomedicine is directed by a fragment of antigen-binding (Fab) against a membrane protein overexpressed in ES cells. Ewing sarcoma is a rare, mostly pediatric bone cancer, with a bad prognosis when metastatic. It is an orphan disease with very few therapeutic options. The oncogene we shall target is a fusion oncogene EWS-FLI1 considered as the main cause of Ewing sarcoma. EWS-FLI1 is a paradigm of fusion oncogenes over the 300 discovered in human up to now. siRNA inhibit with a high specificity the expression of any human gene, and can play a key role in treating many diseases (cancers, cardiovascular and neurological diseases). However they are quickly degraded in organism and penetrate poorly in cells. One solution is to use nanocarriers to deliver active siRNA in the cytoplasm where their antisense effect takes place. Various polymeric nanocarriers have been used, but very few have reached clinical trials. We propose an alternative carrier made of a diamond nanocrystal core with a surface chemically modified to bind siRNA electrostatically and bear the Fab intended for targeting. Nanodiamonds present several interests: (i) they are chemically inert and non toxic on cell cultures; (ii) they can be made intrinsically fluorescent or radioactive, hence traceable on long term scale, by embedding color center or tritium, respectively; (iii) their surface can be modified by a variety of methods to provide cationic or anionic charges or to covalently bind biomolecules. The first task will be to synthesize ND/siRNA/Fab complexes of different types (size, traceable properties, surface functions). Then, the toxicity, pharmacokinetics, and biodistribution will be determined in ES tumor xenografted in mice (including a metastatic model) taking advantage of the intrinsic traceability. The localization of the complex within metastases responsible for the low survival rate will be examined carefully. Finally, the therapeutic efficacy will include in vitro and in vivo measurement of EWS-FLI1 inhibition and of the regression of primary and metastatic tumors. The project should give rise to therapeutic solutions ready to enter regulatory preclinical developments.