Normal Helium 3: a Mott-Stoner liquid

A physical picture of normal liquid $^3$He, which accounts for both ``almost localized'' and ``almost ferromagnetic'' aspects, is proposed and confronted to experiments.Comment: 4 pages, RevTeX3.0, 1 EPS figur

Superradiant Quantum Materials

There is currently great interest in the strong coupling between the quantized photon field of a cavity and electronic or other degrees of freedom in materials. A major goal is the creation of novel collective states entangling photons with those degrees of freedom. Here we show that the cooperative effect between strong electron interactions in quantum materials and the long-range correlations induced by the photon field leads to the stabilization of coherent phases of light and matter. By studying a two-band model of interacting electrons coupled to a cavity field, we show that a phase characterized by the simultaneous condensation of excitons and photon superradiance can be realized, hence stabilizing and intertwining two collective phenomena which are rather elusive in the absence of this cooperative effect.Comment: 5 pages, 4 figure

Strongly correlated bosons and fermions in optical lattices

These lectures are an introduction to the physics of strongly correlated fermions and bosons. They are specially targeted for the experimental realizations that have been provided by cold atomic gases in optical lattices.Comment: Lectures presented at the Les Houches summer school 2010: "Many-Body Physics with Ultracold Gases", organized by C. Salomon and G. V. Shlyapniko

Thermoelectric transport and Peltier cooling of cold atomic gases

This brief review presents the emerging field of mesoscopic physics with cold atoms, with an emphasis on thermal and 'thermoelectric' transport, i.e. coupled transport of particle and entropy. We review in particular the comparison between theoretically predited and experimentally observed thermoelectric effects in such systems. We also show how combining well designed transport properties and evaporative cooling leads to an equivalent of the Peltier effect with cold atoms, which can be used as a new cooling procedure with improved cooling power and efficiency compared to the evaporative cooling currently used in atomic gases. This could lead to a new generation of experiments probing strong correlation effects of ultracold fermionic atoms at low temperatures.Comment: 33 pages, 9 figures, Review. To be published in the special issue "Mesoscopic Thermoelectric Phenomena" of C. R. Physique 17 (2016