Temperature Chaos, Rejuvenation and Memory in Migdal-Kadanoff Spin Glasses

Munetaka Sasaki (1) , Olivier C. Martin (2)

1 ISSP - Institute for Solid State Physics [Tokyo]
2 LPTMS - Laboratoire de Physique Théorique et Modèles Statistiques

We use simulations within the Migdal-Kadanoff real space renormalization approach to probe the scales relevant for rejuvenation and memory in spin glasses. One of the central questions concerns the role of temperature chaos. First we investigate scaling laws of equilibrium temperature chaos, finding super-exponential decay of correlations but no chaos for the total free energy. Then we perform out of equilibrium simulations that follow experimental protocols. We find that: (1) rejuvenation arises at a length scale smaller than the ``overlap length'' l(T,T'); (2) memory survives even if equilibration goes out to length scales much larger than l(T,T').

Mots clés: Disordered Systems and Neural Networks; Statistical Mechanics

Domaines: Systèmes désordonnés et réseaux de neurones [cond-mat.dis-nn]; Mécanique statistique [cond-mat.stat-mech]

Munetaka Sasaki, Olivier C. Martin. Temperature Chaos, Rejuvenation and Memory in Migdal-Kadanoff Spin Glasses. Physical Review Letters, 2003, 91, pp.097201. ⟨hal-00002271⟩