Matterandlight are intimately linked in our modelling of the physical world. From the development of quantum theory to the invention of the laser, the interaction between Atoms and Radiation has played a central role in the development of today's science and technology.

In recent decades, a paradoxical application of the matter-radiation interaction has emerged. While light is traditionally associated with the notion of heat, it has become clear that irradiating a gas with carefully selected laser beams can, on the contrary, give rise to remarkably efficient cooling. This cooling enables the lowest temperatures ever measured to be reached. The result is a " quantum matter " with properties radically different from those of ordinary fluids. Cold atoms form the basis of a new metrology of time and space, with applications in fields as diverse as navigation, telecommunications and geophysics.

The lectures and research associated with the Chair aim to deepen our understanding of theproperties of thisultra-cold matter. Recent results have focused on reduced-dimension physics - planar fluidsinparticular - the behavior ofspine atomgases, i.e. thosewithaninternal degree of freedom, and the study of these gases in the presence ofa gauge field, in direct relation to thequantum Hall effect known for solid bodies.

More generally, we aim to show how these ultra-cold gases can be used to model situations encountered in other fields, from nuclear physics to astrophysics, via materials science ; in other words, we are exploring how atoms judiciously coupled to electromagnetic radiation can constitute " simulators " with which wehope to understand the behavior of other, more difficult-to-control quantum systems.