How can disorder turn into long-range order at high magnetic fields ?
Mardi 3 octobre 2017 13:30
- Duree : 1 heure
Lieu : LNCMI, salle de conférences "René Pauthenet" (bâtiment J, 2ème étage) - 25 rue des martyrs - 38000 Grenoble
Orateur : Maxime DUPONT (Laboratoire de Physique Théorique, IRSAMC, Université de Toulouse, CNRS, UPS, France)
Résumé : It is known that a class of quantum antiferromagnets displays a Bose-Einstein condensation (BEC) at high magnetic field, as experimentally observed in numerous Mott insulators. In this scope, I will first present the antiferromagnetic insulator compound NiCl2-4SC(NH2)2 (DTN for short) which exhibits BEC. Going beyond this clean case, doping with bromine impurities (randomly substituting Cl) was believed to provide the first experimental realization of the elusive Bose-glass phase in a quantum magnet [1] at high magnetic fields. In three consecutive experimental and theoretical works [2-4], we discovered that this many-body localized phase is actually undermined by the resurgence of long-range order with a condensation of the underlying impurities degree of freedom, leading to a novel “order-by-disorder” mechanism.
[1] R. Yu et al. Nature 489, 379–384 (2012)
[2] A. Orlova et al. Phys. Rev. Lett. 118, 067203 (2017)
[3] M. Dupont et al. Phys. Rev. Lett. 118, 067204 (2017)
[4] M. Dupont et al. Phys. Rev. B 96, 024442 (2017)
Contact : anne-laure.barra@lncmi.cnrs.fr
Discipline évènement : (Physique)
Entité organisatrice : (LNCMI)
Nature évènement : (Séminaire)
Site de l'évènement : Polygone scientifique
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