14 research outputs found

    Using a hybrid superconducting-ferromagnetic tip as a magnetic scanning tunneling microscope

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    Approaching a two-component tip made of a superconductor (S) and a ferromagnet (F) from a magnetic sample allows for two distinct tunneling processes between the ferromagnets, through S: i) Charge and spin are conserved; ii) Charge and spin are reversed, e.g. a Cooper pair flows from S, one electron going into F, the other into the sample. At subgap voltages, this allows two currents to flow from the tip : one is insensitive to the spin polarizations and allows for surface topography, the other directly tracks the relative spin polarizations of F and the sample. The whole device acts as a STM sensitive to the spin polarization at the Fermi level (MSTM). Its sensitivity is studied and optimized with respect to the tip geometry.Comment: 12 pages, 2 figure

    Spintronics: Fundamentals and applications

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    Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject, including both recent advances and well-established results. The primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport in semiconductors and metals. Spin transport differs from charge transport in that spin is a nonconserved quantity in solids due to spin-orbit and hyperfine coupling. The authors discuss in detail spin decoherence mechanisms in metals and semiconductors. Various theories of spin injection and spin-polarized transport are applied to hybrid structures relevant to spin-based devices and fundamental studies of materials properties. Experimental work is reviewed with the emphasis on projected applications, in which external electric and magnetic fields and illumination by light will be used to control spin and charge dynamics to create new functionalities not feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes from the published versio

    À l'ouest sans perdre le nord : liber amicorum JosĂ© Gomez de Soto

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    International audienceSpĂ©cialiste des Ăąges des mĂ©taux, chercheur au CNRS, JosĂ© Gomez de Soto fait partie de ces scientifiques qui savent partager. Le responsable de fouille et l’enseignant qu’il fut a entraĂźnĂ© derriĂšre lui plusieurs gĂ©nĂ©rations d’archĂ©ologues qui ont tenu Ă  le cĂ©lĂ©brer dans cet ouvrage. Par la qualitĂ© des contributions rĂ©unies, ce liber amicorum n’est pas seulement un hommage Ă  l’Ɠuvre scientifique de JosĂ©, c’est aussi un tĂ©moignage d’amitiĂ© et de gratitude envers cet homme et ce chercheur d’exception.Le prĂ©sent recueil de textes est Ă  son image, et conforme Ă  ce que sont des “mĂ©langes”, homogĂ©nĂ©isant des Ă©lĂ©ments plus ou moins diffĂ©rents pour en constituer un tout.La frange ouest de la France y a la part belle, mais le nord, l’est, le sud aussi un peu, et le plus lointain, sont Ă©galement traversĂ©s. De mĂ©galithes en grottes sĂ©pulcrales, d’enceintes nĂ©olithiques en tumulus, d’habitats en dĂ©pĂŽts, la diversitĂ© des contextes prĂ©sentĂ©s ici est Ă  l’image de celle de ses centres d’intĂ©rĂȘt.Toujours un peu Ă  l’ouest, mais sans jamais perdre le nord

    À l'ouest sans perdre le nord : liber amicorum JosĂ© Gomez de Soto

    No full text
    International audienceSpĂ©cialiste des Ăąges des mĂ©taux, chercheur au CNRS, JosĂ© Gomez de Soto fait partie de ces scientifiques qui savent partager. Le responsable de fouille et l’enseignant qu’il fut a entraĂźnĂ© derriĂšre lui plusieurs gĂ©nĂ©rations d’archĂ©ologues qui ont tenu Ă  le cĂ©lĂ©brer dans cet ouvrage. Par la qualitĂ© des contributions rĂ©unies, ce liber amicorum n’est pas seulement un hommage Ă  l’Ɠuvre scientifique de JosĂ©, c’est aussi un tĂ©moignage d’amitiĂ© et de gratitude envers cet homme et ce chercheur d’exception.Le prĂ©sent recueil de textes est Ă  son image, et conforme Ă  ce que sont des “mĂ©langes”, homogĂ©nĂ©isant des Ă©lĂ©ments plus ou moins diffĂ©rents pour en constituer un tout.La frange ouest de la France y a la part belle, mais le nord, l’est, le sud aussi un peu, et le plus lointain, sont Ă©galement traversĂ©s. De mĂ©galithes en grottes sĂ©pulcrales, d’enceintes nĂ©olithiques en tumulus, d’habitats en dĂ©pĂŽts, la diversitĂ© des contextes prĂ©sentĂ©s ici est Ă  l’image de celle de ses centres d’intĂ©rĂȘt.Toujours un peu Ă  l’ouest, mais sans jamais perdre le nord

    À l'ouest sans perdre le nord : liber amicorum JosĂ© Gomez de Soto

    No full text
    International audienceSpĂ©cialiste des Ăąges des mĂ©taux, chercheur au CNRS, JosĂ© Gomez de Soto fait partie de ces scientifiques qui savent partager. Le responsable de fouille et l’enseignant qu’il fut a entraĂźnĂ© derriĂšre lui plusieurs gĂ©nĂ©rations d’archĂ©ologues qui ont tenu Ă  le cĂ©lĂ©brer dans cet ouvrage. Par la qualitĂ© des contributions rĂ©unies, ce liber amicorum n’est pas seulement un hommage Ă  l’Ɠuvre scientifique de JosĂ©, c’est aussi un tĂ©moignage d’amitiĂ© et de gratitude envers cet homme et ce chercheur d’exception.Le prĂ©sent recueil de textes est Ă  son image, et conforme Ă  ce que sont des “mĂ©langes”, homogĂ©nĂ©isant des Ă©lĂ©ments plus ou moins diffĂ©rents pour en constituer un tout.La frange ouest de la France y a la part belle, mais le nord, l’est, le sud aussi un peu, et le plus lointain, sont Ă©galement traversĂ©s. De mĂ©galithes en grottes sĂ©pulcrales, d’enceintes nĂ©olithiques en tumulus, d’habitats en dĂ©pĂŽts, la diversitĂ© des contextes prĂ©sentĂ©s ici est Ă  l’image de celle de ses centres d’intĂ©rĂȘt.Toujours un peu Ă  l’ouest, mais sans jamais perdre le nord

    Comparison of passive heat or exercise induced dehydration on renal water and electrolyte excretion: the hormonal involvement

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    Contains fulltext : 151642.pdf (publisher's version ) (Closed access)Adolescents tend to form friendships with similar peers and, in turn, their friends further influence adolescents' behaviors and attitudes. Emerging work has shown that these selection and influence processes also might extend to bully victimization. However, no prior work has examined selection and influence effects involved in bully victimization within cliques, despite theoretical account emphasizing the importance of cliques in this regard. This study examined selection and influence processes in adolescence regarding bully victimization both at the level of the entire friendship network and the level of cliques. We used a two-wave design (5-month interval). Participants were 543 adolescents (50.1 % male, Mage = 15.8) in secondary education. Stochastic actor-based models indicated that at the level of the larger friendship network, adolescents tended to select friends with similar levels of bully victimization as they themselves. In addition, adolescent friends influenced each other in terms of bully victimization over time. Actor Parter Interdependence models showed that similarities in bully victimization between clique members were not due to selection of clique members. For boys, average clique bully victimization predicted individual bully victimization over time (influence), but not vice versa. No influence was found for girls, indicating that different mechanisms may underlie friend influence on bully victimization for girls and boys. The differences in results at the level of the larger friendship network versus the clique emphasize the importance of taking the type of friendship ties into account in research on selection and influence processes involved in bully victimization.13 p
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