Disorder in low dimensions : localisation effects in spin glass wires and cold atoms

In this paper, we review the recent activity of our group on the study of disorder effects on systems displaying phase coherence. These studies have focused on both the electronic transport through mesoscopic metallic spin glasses, and cold atomic gases trapped in a disordered potential

Cross-Over between universality classes in a magnetically disordered metallic wire

In this article we present numerical results of conduction in a disordered quasi-1D wire in the possible presence of magnetic impurities. Our analysis leads us to the study of universal properties in different conduction regimes such as the localized and metallic ones. In particular, we analyse the cross-over between universality classes occurring when the strength of magnetic disorder is increased. For this purpose, we use a numerical Landauer approach, and derive the scattering matrix of the wire from electron's Green's function.Comment: Final version, accepted for publication in New Journ. of Physics, 27 pages, 28 figures. Replaces the earlier shorter preprint arXiv:0910.427

Front Microbiol

Brettanomyces bruxellensis is the main spoilage microbial agent in red wines. The use of fungal chitosan has been authorized since 2009 as a curative treatment to eliminate this yeast in conventional wines and in 2018 in organic wines. As this species is known to exhibit great genetic and phenotypic diversity, we examined whether all the strains responded the same way to chitosan treatment. A collection of 53 strains of was used. In the conditions of the reference test, all were at least temporarily affected by the addition of chitosan to wine, with significant decrease of cultivable population. Some (41%) were very sensitive and no cultivable yeast was detected in wine or lees after 3 days of treatment, while others (13%) were tolerant and, after a slight drop in cultivability, resumed growth between 3 and 10 days and remained able to produce spoilage compounds. There were also many strains with intermediate behavior. The strain behavior was only partially linked to the strain genetic group. This behavior was little modulated by the physiological state of the strain or the dose of chitosan used (within the limits of the authorized doses). On the other hand, for a given strain, the sensitivity to chitosan treatment was modulated by the chitosan used and by the properties of the wine in which the treatment was carried out.Recherches sur l’origine et les effets secondaires des propriétés stabilisantes du chitosane fongique dans le vi

Transport électronique et Verres de Spins

The results reported in this thesis contribute to the understanding of disordered systems, to mesoscopic physics on the one hand, and to the physics of spin glasses on the other hand. The first part of this thesis studies numerically coherent electronic transport in a non magnetic metal accurately doped with frozen magnetic impurities (a low temperature spin glass). Thanks to a recursive code that calculates the two terminal conductance of the system, we study in detail the metallic regime of conduction (large conductance) as well as the insulating regime (small conductance). In both regimes, we highlight a universal behavior of the system. Moreover, a study of correlations between the conductance of different spin configurations of impurities allows us to link these correlations with correlations between spin configurations. This study opens the route for the first experimental determination of the overlap via transport measurements. A second part of this thesis deals with the study of the mean field Sherrington-Kirkpatrick model, which describes the low temperature phase of an Ising spin glass. We are interested here in the generalization of this model to quantum spins (i.e including the possibility to flip by quantum tunneling) of this classical model that was well studied during the past thirty years. We deduce analytically motion equations at the semi-classical level, for which the influence of quantum tunneling is weak, and we compare them with the classical case. We finally solve numerically these equations using a pseudo-spectral method

Les Thermes du Levant à Leptis Magna : présentation architecturale et périodisation générale

The Thermes du Levant, in the west part of the city of Lepcis Magna, were discovered by the Mission archéologique française en Libye in 1994. They comprise of two adjacent areas. The first, accessible from a seashore platea, consists of some shops, the entranceways and a pump pit filled by a remarkable underground network of cisterns and galleries. The second, comprises the rooms of classical roman baths (including two warm rooms) and their pools, the heating chamber and annexes, all preserved to a height of 6 metres. The older soils date from the 1st century BC, but the baths would have only worked during the 2nd and 3rd centuries AD probably due to earthquakes. They were then converted into mills and bakeries, then into poor dwellings during the 4th and 5th centuries. Quickly covered by sand, they were unknown till now. Their excavation is yet to be completed.Les Thermes du Levant, dans le secteur est de la cité de Leptis Magna, ont été mis au jour par la Mission archéologique française en Libye en 1994. Ils sont constitués de deux ensembles distincts connectés. L’un, desservi par une platea à portique qui suit le rivage, comporte diverses échoppes, les vestibules d’accès et la fosse d’une pompe alimentée par un remarquable réseau de galeries et de citernes souterraines. L’autre comprend les classiques salles thermales (dont deux tièdes) et leurs piscines, la fournaise et diverses annexes, le tout est conservé sur 6 m de hauteur. Les sols les plus anciens de l’édifice datent de la fin du Ier siècle av. J.-C., mais les thermes n’auraient fonctionné qu’aux IIe et IIIe s., probablement du fait de séismes. Ils ont été convertis en meunerie/ boulangerie, puis en habitations précaires, aux IVe-Ve siècles. Rapidement ensablés, ils avaient été totalement ignorés jusqu’à maintenant. Leur fouille reste encore à terminer.Paulin Michel, Dagnas Guillaume. Les Thermes du Levant à Leptis Magna : présentation architecturale et périodisation générale. In: Antiquités africaines, 46-48,2010. pp. 99-145

Quelques considérations sur les inventeurs (sains d'esprit, dégénérés, aliénés)

Thèse : Médecine : Université de Bordeaux : 1903N° d'ordre : 8

Les thermes du Levant à Leptis Magna (Libye)

International audienc

Les thermes du Levant à Leptis Magna (Libye)

International audienc

Les thermes du Levant à Leptis Magna : présentation architecturale et périodisation générale

International audienc

Les thermes du Levant à Leptis Magna : présentation architecturale et périodisation générale

International audienc