Age reinitialization in hierarchical relaxation models for spin-glass dynamics

We show that thermal relaxation on a tree structure is reinitialized bq a temperature pulse, similarly to the experimental behavior of spin-glasses. The models' behavior originates from fast dynamical modes being excited -a mechanism which goes beyond the usual quasi-equilibrium description of slow relaxation based on the concept of a free-energy landscape. We demonstrate the excellent agreement of the model predictions with the thermoremanent magnetization experiments and discuss some of the implications of the results for the understanding of complex relaxation.