Publication : t01/158
Out-of-equilibrium dynamics of a quantum Heisenberg spin glass
Biroli G. (Center for Materials Theory, Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, USA)Parcollet O. (Center for Materials Theory, Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, USA)
Abstract:Année de publication : 2002
We study the out of equilibrium dynamics of the infinite range quantum Heisenberg spin glass model coupled to a thermal relaxation bath. The $SU (2)$ spin algebra is generalized to $SU (N)$ and we analyze the large-$N$ limit. The model displays a dynamical phase transition between a paramagnetic and a glassy phase. In the latter, the system remains out of equilibrium and displays an aging phenomenon, which we characterize using both analytical and numerical methods. In the aging regime, the quantum fluctuation-dissipation relation is violated and replaced at very long time by its classical generalization, as in models involving simple spin algebras studied previously. We also discuss the effect of a finite coupling to the relaxation baths and their possible forms. This work completes and justifies previous studies on this model using a static approach.
Publication extérieure au service
Revue : Phys. Rev. B 65 094414 (2002)
DOI : 10.1103/PhysRevB.65.094414
Preprint : arXiv:cond-mat/0105001
Lien : http://link.aps.org/abstract/PRB/v65/p094414
Langue : Anglais
Fichier(s) à télécharger :
publi.pdf
