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This thesis pretends to be another step in the development of numerical research in disordered systems. Specifically, we will focus on spin glasses which have demonstrated to be a fertile field from both, experimental and theoretical approaches. Throughout this thesis, we will discuss a variety of interesting phenomenons and we will also open new avenues to previously unexplored effects in the context of spin glasses. However, without a doubt, the leitmotiv conducting this thesis is the role of numerical simulations as a valuable tool to explore spin-glass physics. This thesis is organized into five different parts. The first part, containing the Chapter 1, is focused on introducing the spin glasses to the reader. The second part, containing the Chapter 2, is dedicated to discussing the metastate. The third part, shaped by the Chapter 3 and Chapter 4, is devoted to studying the off-equilibrium dynamics in spin glasses. Specifically, Chapter 3 is focused on discussing the growth of the coherence length in spin glasses, a key quantity that characterizes the off-equilibrium evolution of those systems. In Chapter 4 we will discuss an interesting phenomenon: the Mpemba effect. The fourth part, containing the Chapter 5, Chapter 6 and Chapter 7 is devoted to study the Temperature Chaos phenomenon in spin glasses. In Chapter 5 we introduce the main historical results on Temperature Chaos, from its origins to the last steps. In Chapter 6 we study equilibrated spin glasses and we characterize the Temperature Chaos from a static and a dynamical point of view. In Chapter 7 we tackle the problem of characterizing Temperature Chaos in off-equilibrium dynamics. The fifth and last part of the main body of the thesis corresponds to the conclusions.
We find a dynamic effect in the non-equilibrium dynamics of a spin glass that closely parallels equilibrium temperature chaos. This effect, that we name dynamic temperature chaos, is spatially heterogeneous to a large degree. The key controlling quan
We have introduced a variational method to improve the computation of integrated correlation times in the Parallel Tempering Dynamics, obtaining a better estimate (a lower bound, at least) of the exponential correlation time. Using this determination
We study zero-temperature, stochastic Ising models sigma(t) on a d-dimensional cubic lattice with (disordered) nearest-neighbor couplings independently chosen from a distribution mu on R and an initial spin configuration chosen uniformly at random. G
Domain-wall free-energy $delta F$, entropy $delta S$, and the correlation function, $C_{rm temp}$, of $delta F$ are measured independently in the four-dimensional $pm J$ Edwards-Anderson (EA) Ising spin glass. The stiffness exponent $theta$, the frac
The aging in a Heisenberg-like spin glass Ag(11 at% Mn) is investigated by measurements of the zero field cooled magnetic relaxation at a constant temperature after small temperature shifts $|Delta T/T_g| < 0.012$. A crossover from fully accumulative