Related papers: Ageing and crystallization in a lattice glass mode…
We use X-Ray Photon Correlation Spectroscopy to investigate the structural relaxation process in a metallic glass on the atomic length scale. We report evidence for a dynamical crossover between the supercooled liquid phase and the…
We study various models of independent particles hopping between energy `traps' with a density of energy barriers $\rho(E)$, on a $d$ dimensional lattice or on a fully connected lattice. If $\rho(E)$ decays exponentially, a true dynamical…
The nature of glassy states in realistic finite dimensions is still under fierce debate. Lattice models can offer valuable insights and facilitate deeper theoretical understanding. Recently, a disordered-interacting lattice model with…
Aging in a single crystal spin glass ($\mathrm{Cu}_{0.92}\mathrm{Mn}_{0.08}$) has been measured using ac susceptibility techniques over a temperature range of $0.3 - 0.8 \, T_g$. In these studies, traditional aging experiments (or…
In the framework of recently introduced frustrated lattice gas models, we study the out of equilibrium dynamical processes during the compaction process in granular media. We find irreversible-reversible cycles in agreement with recent…
This thesis sums up the research work I performed as a PhD student in Sapienza Universit\`a di Roma, and \'Ecole Normale Sup\'erieure, Paris, under the joint supervision of Prof. Giorgio Parisi and Dr. Francesco Zamponi. The thesis focuses…
Using a non-local Monte Carlo algorithm, we study the aging of a fragile glass, being able to follow it up to equilibibrium down to 0.89 Tmc (Tmc is the Mode-Coupling temperature) and up to unprecedentedly large waiting times at lower…
We propose that there exists a generic class of glass forming systems that have competing states (of crystalline order or not) which are locally close in energy to the ground state (which is typically unique). Upon cooling, such systems…
Volume and enthalpy relaxation of glasses after a sudden temperature change has been extensively studied since Kovacs seminal work. One observes an asymmetric approach to equilibrium upon cooling versus heating and, more…
We have compared aging phenomena in the Fe_{0.5}Mn_{0.5}TiO_3 Ising spin glass and in the CdCr_{1.7}In_{0.3}S_4 Heisenberg-like spin glass by means of low-frequency ac susceptibility measurements. At constant temperature, aging obeys the…
We study the non-equilibrium behavior of three-dimensional spin glasses in the Migdal-Kadanoff approximation, that is on a hierarchical lattice. In this approximation the model has an unique ground state and equilibrium properties correctly…
We demonstrate non-equilibrium scaling laws for the aging dynamics in glass formers that emerge from combining a recent application of Onsager's theory of irreversible processes with the equilibrium scaling laws of glassy dynamics.…
Using Monte Carlo simulations, we have studied the relaxation of energy of the three-dimensional Ising spin-glass model in aging process. Our finite-size-scaling analysis on the isothermal energy decay after the quench suggests strongly…
History-dependence and ageing are studied in the low-temperature glass phase of a long-range periodic Josephson array. This model is characterized by two parameters, the number of wires ($2N$) and the flux per unit strip ($\alpha$); in the…
In this note we revisit the Kovacs effect, concerning the way in which the volume of a glass-forming liquid, which has been driven out of equilibrium, changes with time while the system evolves towards a metastable state. The theoret- ical…
We introduce an exactly solvable model for glassy dynamics with many relaxational modes, each one characterized by a different relaxational time-scale. Analytical solution of the aging dynamics at low temperatures shows that a…
We present a comprehensive study of non-equilibrium phenomena in the low temperature phase of the Edwards-Anderson Gaussian spin glass in 3 and 4 spatial dimensions. Many effects can be understood in terms of a time dependent coherence…
We discuss the relaxation dynamics of a simple structural glass which has been quenched below its glass transition temperature. We demonstrate that time correlation functions show strong aging effects and investigate in what way the…
Using Monte Carlo simulations we study cooling-rate effects in a three-dimensional Ising model with four-spin interaction. During coarsening, this model develops growing energy barriers which at low temperature lead to very slow dynamics.…
We consider two systems of Ising spins with plaquette interactions. They are simple models of glasses which have dual representations as kinetically constrained systems. These models allow an explicit analysis using the mosaic, or entropic…