Although sugars play a crucial role in many biological processes, their uses in therapeutics remain limited due to their low stability. That’s why organic chemists are constantly pushed to develop new access to original analogues. In particular, replacement of natural anomeric link by C-C mimics (C-glycosides) is widely explored due to their higher chemical and enzymatic stability as well as their conformational similarity compared to natural C-O and C-N analogues. These specific aspects have made these structures potentially valuable enzyme inhibitors. Current synthetic routes of C-glycosides involve several steps and use frequently strong bases, which narrow their development. This last decade, access to complex molecules via C-H functionalization reactions is became very attractive since this strategy avoid to go through pre-functionalized intermediates. In order to circle regioselectivity issues inherent to these transformations, the uses of directing group is commonly chosen in C-H functionalization catalyzed by metallic complexes. Despite the interest of this type of reaction, examples of metal-catalyzed C-H functionalization of sugar-type substrates are scarce and involve in the most of the case intramolecular radical processes. In this project, our goal is to develop new general and efficient synthetic routes to C-aryl-glycosides of interest via metal-catalyzed C-H functionalization reaction of the C-H anomeric bond. These structures showed already several interesting biological activities in diabete 2 treatment for example. The challenge associated to this project is to mono-functionalize complex sugar substrates possessing many similar C-H bonds. Our strategy consists in introducing a directing group on the desired starting glycoside. The position of this directing group is crucial and will be soundly chosen. The first part of the project is interested in the synthesis of C-aryl-glycoside carboxamides as N-acetyl-glycoside mimics. These structures will be obtained via a metal-catalyzed C-H functionalization reaction of unsaturated glycal substrates directed by an amido-group in C2 position. This directing group will be previously installed via a pallado-catalyzed aminocarbonylation process recently developed in our laboratory, between a 2-iodoglycal and an amine in presence of « CO » source. The second part of the project tends to develop access to C-aryl-glycosides via a metal-catalyzed functionalization from saturated glycosides. Our strategy consists in introducing a silylated directing group, easily installed on hydroxyl, on the anomeric hemiacetal function. This type of directing group offer the possibility to access to two types of structures: C-glycosides and keto-glycosides, depending on the cleavage method used at the end of the reaction. In a third part, due to environmental concerns which tend to reduce number of synthetic steps in complex molecule synthesis, the development of metal-catalyzed dehydrogenative C-H functionalization reactions will be planned on the same starting substrates envisaged in the two first methodologies. In this last part, the objective is to couple our glycosides with non pre-functionalized aryl partners. Post-functionalization, deprotection of obtained compounds as well as application of the developed methods to the synthesis of molecules of therapeutical interest will be investigated at the end of each part.

The magnetic properties of nanostructures have been intensely investigated in the last few years since it offers the opportunity to unfold new physical phenomena and design novel devices and applications all at once. An example of such simultaneous progress of fundamental understanding and practical developments can be found in the recent trend consisting in the electrical manipulation of magnetic properties. This opens the way to the design of spintronics devices in which the application of some magnetic field is no longer necessary. Up to now, the research on this topic has essentially focused on manipulating the magnetization of ferromagnetic nanostructures, yet some recent theoretical results suggest that it is also possible to control the magnetic ordering in antiferromagnets (AF) with an electric field or a current, in a more efficient way than for ferromagnets. Antiferromagnets would then play an active role, and not merely act as complementary layers in complex stacking as they do in present devices. The aim of the ELECTR-AF project is to explore the physical mechanisms underlying the electrical control of AF ordering. To unravel the intrinsic phenomena, we choose to focus on model systems. We will focus on heterostructures build around chromium epitaxial thin films, since the AF ordering of bulk Cr is both well known and easy to manipulate. Indeed, high quality chromium samples exhibit a spin density wave (SDW) ordering, the period of the modulated structure being incommensurate with the crystalline lattice. These model AF layers will be included in model heterostructures: we will grow epitaxial bcc metal/MgO/bcc metal trilayers (Cr being either the top or bottom metallic layer). This class of system has played a crucial role in the detailed understanding of spin-dependent tunnelling, and we will thus be able to build on the accumulated knowledge to explore the physics of spin polarized transport in antiferromagnets. We will first carry out thorough studies of the magnetic properties of Cr thin films and of the Cr/MgO interface, in order to obtain a detailed knowledge of our system. We will follow two distinct strategies to manipulate the magnetic ordering of Cr layers: - we will apply a voltage across an MgO layer in order to accumulate charges at the Cr/MgO interface. Given the large sensitivity of Cr to doping, we expect to modify the SDW period. - we will flow a spin polarized current through a Cr layer. We expect to observe spin transfer torque effects, and thus induce switching or precession of Cr ordering parameter. To observe the evolution of Cr magnetic ordering with the external perturbation, we will combine diffraction and magnetotransport measurements. One challenge of this project is to obtain information on the elusive magnetic ordering of Cr. Neutron diffraction is the ideal tool to do so, since it gave direct access to the properties of the SDW (direction of propagation, period, polarization). This project will give us the impetus to push the limits of the technique. We will also use synchrotron-based techniques and benefit from the latest developments in terms of electronic microscopy. The experimental aspects of this project are thus highly ambitious, but we are plainly confident these challenging experiments can be done, in the light of feasibility tests we have run and recent developments in the different techniques.

Quantum physics allows us to make computers whose computing power overcomes by large that of classical computers, whatever their future progress. This recent discovery has triggered a huge research effort for making quantum processors. Nowadays, the most advanced implementations are based on trapped ions and superconducting qubit circuits, and elementary instances of quantum algorithms were demonstrated with these systems and with some other ones. The Quantronics group at CEA-Paris-Saclay led by the applicant, Daniel Esteve, has played a key role in the development of superconducting qubits since its beginning. Despite the unsolved challenges raised by maintaining quantum coherence during processor evolution, and by the scalability issue, major players in information processing such as IBM, Microsoft, Intel or Google have developed since a few years in-house research and/or strong academic partnerships in order to mitigate the detrimental effect that a quantum breakthrough would have in their activities. Atos, a leading company in high performance computing, has similarly developed its own quantum computing activity. Since 2016, its teams develop quantum software and a powerful FPGA-based emulator of a quantum computer. Besides, Atos has initiated a collaboration with the Quantronics group of the applicant, and supports a first forthcoming CIFRE PhD thesis research for detecting a new type of quantum bit in the applicant laboratory. The work programme for this industrial chair first aims at providing to Atos the high level scientific watch in the field of quantum computing that the applicant and his team, who are well-recognized and well-connected to leading teams worldwide, can deliver. A second goal consists in providing to Atos physical models of different qubits embedding noise models, processing time, communication models in order to simulate them efficiently with the emulator Atos is presently developing. The goal is to enable Atos to get numerical metrics to be used for algorithm optimization in a given qubit platform. This analysis will be carried-out in-depth for all quantum bits developed by CEA. The main research objective is to develop new quantum bits with better quantum coherence than superconducting quantum bits. Given their limitations, there is no operational architecture for solving the quantum error correction issue in a superconducting processor when scaling the size. Indeed, the fault-tolerant architecture compatible with superconducting quantum bit error thresholds, namely the surface-code architecture, requires a prohibitive overhead in terms of physical qubit resources. In order to mitigate and solve these challenges, The applicant and his team propose to use nuclear spins as quantum bits, for which quantum error correction would be much less of a problem. When these nuclear spins are coupled to electronic spins by the hyperfine interaction, and these electronic spins are coupled to superconducting microwave resonators that transmit photons that can be measured, the combination of all these quantum systems provides an original attractive route towards a new quantum computing platform based on very coherent quantum bits. The potential route such a platform would have is of great interest for Atos, and applicant team has already obtained significant preliminary results in this direction. Last but not least, the collaboration between Atos and CEA in the field of quantum computing would even more connect Atos with the microfabrication capacity of CEA if an industrial development is foreseen.