BEGIN:VCALENDAR VERSION:2.0 PRODID:-//SPIP/Plugin Agenda//NONSGML v1.0//FR X-WR-TIMEZONE:Europe/Paris CALSCALE:GREGORIAN X-WR-CALNAME;VALUE=TEXT:Soutenance de thèse de Juan Trastoy Quintela -- Unité Mixte de Physique CNRS/Thales X-WR-RELCALID: BEGIN:VEVENT SUMMARY:Soutenance de thèse de Juan Trastoy Quintela UID:20151219T152809Z-a155-e5@ DTSTAMP:20151219T152809Z DTSTART:20141205T130000Z DTEND:20141205T163000Z CREATED:20151219T152809Z LAST-MODIFIED:20151219T142810Z ORGANIZER;CN=CNRS-Thales[] ATTENDEE:Juan Trastoy Quintela DESCRIPTION:Superconducting flux quanta in nanostructured YBa2Cu3O7-δ films constitute a model to study the general problem of interacting particles in a potential-energy landscape. Using O+ ion irradiation through a mask defined via electron-beam lithography\, ordered nanometric regions with a depressed local critical temperature can be defined to precisely engineer the vortex energy landscape. A detailed characterization of this artificial pinning’s strength with temperature and vortex velocity is given\, as well as a study of the vortex phase diagram and the associated thermodynamic phase transition. Thanks to the ability to modulate the superconducting condensate at the nanoscale\, a new mechanism to reversibly switch the vortex energy landscape’s geometry using temperature as a control knob is developed. This is shown through the thermal switching of a geometrically frustrated array into a square periodic one. Finally\, asymmetric vortex motion under a symmetric drive is studied using asymmetric pinning sites. CATEGORIES:Soutenance de thèse de Juan Trastoy Quintela URL: SEQUENCE:0 STATUS:CONFIRMED END:VEVENT END:VCALENDAR