Disorder-Induced Order: From Classical Spin Systems to Ultracold Atomic Gases

Jan Wehr (1) , Armand Niederberger (2) , Laurent Sanchez-Palencia (3) , Maciej Lewenstein (2, 4)

1 Department of Mathematics [University of Arizona]
2 UNIROUEN - Université de Rouen Normandie
3 laboratoire Charles Fabry de l'Institut d'Optique / Optique atomique
4 ITP - Institut für Theoretische Physik [Hannover]

We propose a general mechanism of disorder-induced order by studying a particular case of classical ferromagnetic XY model in a random uniaxial field which breaks the continuous symmetry of the model. We prove rigorously that the system has spontaneous magnetization at temperature T=0, and we present strong evidence that this is also the case for small T>0. We discuss generalizations of this mechanism to various classical spin models and quantum systems. We propose a realization of this phenomenon with ultracold atoms in an optical lattice.

Mots clés: disorder; random; spin; ultracold; XY; Heisenberg; optical lattice; Bose-Einstein

Domaines: Autre [cond-mat.other]

Jan Wehr, Armand Niederberger, Laurent Sanchez-Palencia, Maciej Lewenstein. Disorder-Induced Order: From Classical Spin Systems to Ultracold Atomic Gases. 2006. ⟨hal-00022177v1⟩