At the crossroads of interconnected history, of cultural transfers and of material culture, the scheme Exogenesis proposes to establish the concept of "boundary objects" as objects born to exogenesis, that is to say, the contact with materials, techniques, shapes, skills, or items coming from the antipodes. Since the 16th century, from which era the cognizance of four separate continents has been entrenched, such objects have also been done to perpetuate the link binding Us to the Others (Todorov T., 1989). If the focus on the history of objects is commonplace in the historiography of art, the approach using the most recent anthropological methods relative to objects, conceived as concentrators of meaning, and applying those methods to the study of Europe understood as a meeting ground, is relatively novel. Indeed, using this approach, the focus on "boundary objects" will translate into the analysis of metabolic phenomena. More precisely, studying the usage of “boundary objects” permits to address the history of the construction of the European identity through dialogue with the Others. In such a way, the history of art will itself be driven towards its boundaries. The object as a conveyor is still insufficiently studied as such in the interconnected history of economics, politics or sociology, although it is at times found as an ingredient of historical or artistic speech. A fortiori, the object engendered by a match with an extra-European item has rarely been a point of focus. The scheme proposes to bare remedy to this by pointing to the precise moment when the "exogenous" makes the "endogenous". The making of the meaning of objects by the surrounding context as well as the intrinsic ambivalence of objects (Jeudy-Ballini M.-B. Derlon 2008) are key issues of the scheme. Whatever the surrounding context, nature or provenance, the various terms of production of “boundary objects” will be analysed. "The boundary object" will be regarded as a hub of complex relations which will be analysed from a nexus of selected cases. A paradigmatic "boundary object", the nautilus of the South Pacific Seas mounted by German silversmiths in the late sixteenth century, has been recently described as a "relic holder of a new type” (du Crest S., 2009). Around these particularly meaningful "boundary objects", the status of objects can be addressed effectively so as to further lead the history of art into a more thorough understanding of all its objects. These objects manufactured in Europe, born in the European consciousness, can be understood only in the European context. They do not amount to interbreeding since they have been founders of a European identity they still help build. Taste, imitation, stimulation, hybridisation are essential ingredients of the process of acculturation (Labrusse R., 2011). Based on the analysis of the contextualization, the project proposes to follow the reasons and issues of the production of the « boundary objects » in which the track of their originary exogenesis is still visible. Following this process in the design and making, "boundary objects" have become, and still are, objects of Europe. The relation to the Other, with an interplay of fascination and repulsion, is now made conspicuous by these objects. This process of acculturation generates such "boundary objects" with their shapes. Exogenesis proposes to elicit the related causes and consequences.

Ultracold atoms have emerged as unique tools to study strongly correlated quantum systems. 50 years ago, an intriguing prediction was made by Fulde, Ferrell, Larkin and Ovchinnikov (FFLO) for a superconductor in a magnetic field with imbalanced electron spin populations. They predicted the existence of a superfluid phase where the order parameter is inhomogeneous and oscillates spatially across the sample. In SPIFBOX, we aim at producing and studying this FFLO phase using spin-imbalanced Fermi gases in a box-shaped potential where the density of atoms is uniform. The experimental part of the project will be realized at ENS with two experimental setups using lithium isotopes. The first one is already operational and the flat bottom potential is realized in 3 dimensions by the repulsive mean field of a Bose-Einstein condensate of lithium 7 mixed with the spin-imbalanced Fermi superfluid in an harmonic trap. The second setup is a new generation experiment with much greater flexibility where the flat bottom potential is realized optically using a digital micro-mirror device (DMD). This new machine will enable us to search for the FFLO phase in reduced dimensions for which theoretical predictions and numerical simulations predict a much wider domain of stability for the FFLO state in the phase diagram. The construction of this setup has already started and the SPIFBOX funding will be used to bring it to completion. The theoretical part of the project will be conducted by Giuliano Orso from Paris Diderot University, a specialist of spin imbalanced Fermi systems, and one post-doc that we wish to recruit with SPIFBOX funding. The theory team will determine the optimal conditions for producing the FFLO phase. In particular, exact solutions exist when the fermions live in one dimension for which the existence of the FFLO phase is clearly established. They will also construct the phase diagram when the Fermi gas is mixed with a Bose gas and they will explore the possible stabilization of the FFLO phase in two and three dimensions by controlling the Fermi-Bose interaction strength. Numerical simulations using DMRG and Monte-Carlo methods will be compared to the ENS experimental observations. With the powerful tools of atomic physics, in SPIFBOX we gather together the best experimental conditions for the observation of the FFLO state: no orbital coupling, no disorder, low dimensional samples, and, most importantly, direct spin-resolved imaging of the associated spatial modulation of the atomic cloud. We hope that by solving one of the most outstanding quantum many-body problems, the outcome of SPIFBOX will stimulate new theoretical and experimental concepts at the interface with condensed matter systems. Ultimately this advanced understanding of quantum matter will help to design new materials with unprecedented properties.

I will study out-of-equilibrium dynamics of two-dimensional Bose gases. I will create samples with spatial variations of density, temperature or internal state and investigate their relaxation towards an equilibrium or metastable state. The two main breakthroughs of this project will consist in the experimental realization of (i) quantum transport of bosons through a single-mode channel. (ii) diffusion of a few single-particle impurities in a bath of atoms in another internal state, realizing a quantum Brownian motion experiment. This project is based on an experimental setup that I have recently developed in my team and which is fully operational today. This platform allows us to confine Bose gases in a light sheet restricting the motion of the atoms to a two-dimensional plane and to limit their in-plane motion to an arbitrary-shaped potential. Such a setup, allowing high resolution tailoring of optical potentials is rather original in our field and will offer us a large flexibility to investigate out-of-equilibrium dynamics. A first line of research will be devoted to transport properties of an atomic channel. We will start our work two-dimensional channels of a few micron width, directly available in our setup and hosting many conducting modes. We will study particle and heat transport and characterize the influence of disorder in the channel, which is expected to modify much more strongly the behavior of the normal part with respect to the superfluid part. Then, we will decrease the thickness of the channel to enter the single mode regime and where dramatic effects, like the quantification of heat of conductance, are expected. A second line of research will focus on spin dynamics. The rubidium atom that we use has several internal hyperfine states in the electronic ground state. These states can be easily coupled thanks to a microwave field or a two-photon Raman transition, the latter easily allowing spatial resolution. We will focus on binary mixtures. For instance, we will realize quenches by abruptly superimposing two immiscible internal states and monitor their relaxation, a situation for which we already obtained preliminary results. Then, we will move to the study of the dynamics of an impurity in a bath of atoms in another internal state with tunable interaction. We will develop new tools to measure the motion of a few individual particles with sub-micron resolution. By doing so, we will achieve an experimental configuration where we will observe the diffusive behavior of quantum Brownian particles. A superdiffusive behavior is expected in this regime, which goes beyond the memory-less Markov regime for diffusion. The duration of the project will be of 48 months. A large part of the proposed objectives can be directly tackled in our team. In addition, we will develop new tools (optical aberration correction techniques to achieve single mode channels, spatially resolved Raman coupling with tunable momentum transfer, single-atom fluorescence imaging) to achieve original regimes that goes beyond the current state-of-the-art.

The properties of materials are determined by the order in their most fundamental constituents, generally appearing at sufficiently low temperatures after a phase transition. This generic picture encompasses phenomena as diverse as: the ordering of atoms into perfectly periodic crystals, into superfluid phases for liquid Helium or dilute atomic gases, or even cosmological phenomena. In the case of magnetic materials, usually described in terms of localized spins on lattice, ordering refers to the spatial organization of spins. Examples of such organization are the ferromagnetic and anti-ferromagnetic phases in electronic (spin-1/2) systems: the former is characterized by the parallel alignment of adjacent electron spins in a lattice, while the latter exhibits an antiparallel arrangement of the spins. Spin-exchange interactions are responsible for the emergence of such magnetic quantum phases. Magnetic systems are of the utmost importance for fundamental and applied reasons. A general understanding the nature of magnetic quantum phases of matter requires the study of magnetic systems beyond spin-1/2, where more magnetic phases are possible. Spinor Bose-Einstein condensates (BECs) are highly controllable ultracold atom systems whose internal (spin) degree of freedom allows for different types of magnetic ordering, therefore offering a wider span of magnetic quantum phases. The real time control of the experimental parameters also enables a detailed study of the dynamics of the system out of equilibrium, where topological defects can arise. Furthermore, under spin-orbit coupling (SOC) spinor BECs can display even richer behavior arising from the interplay between ordering in momentum space due to SOC and in real space due to spin exchange. This project aims at the realization of 1D quantum systems with ultracold Na-23 atoms to investigate magnetic quantum phases (with or without SOC) in and out of equilibrium.