Person: Muñoz Sudupe, Antonio
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First Name
Antonio
Last Name
Muñoz Sudupe
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Físicas
Department
Física Teórica
Area
Física Teórica
Identifiers
49 results
Search Results
Now showing 1 - 10 of 49
Item Aging rate of spin glasses from simulations matches experiments(Physical review letters, 2018) Baity Jesi, Marco; Calore, E.; Cruz, A.; Fernández Pérez, Luis Antonio; Gil-Narvión,, J. M.; Gordillo-Guerrero, A.; Íñiguez, D.; Maiorano, A.; Marinari, E.; Martín Mayor, Víctor; Moreno-Gordo, J.; Muñoz Sudupe, Antonio; Navarro, D.; Parisi, G.; Pérez-Gaviro, S.; Ricci-Tersenghi, F.; Ruiz-Lorenzo, J. J.; Seoane Bartolomé, Beatriz; Schifano, S. F.; Tarancón, A.; Tripiccione, R.; Yllanes, D.Experiments on spin glasses can now make precise measurements of the exponent zðTÞ governing the growth of glassy domains, while our computational capabilities allow us to make quantitative predictions for experimental scales. However, experimental and numerical values for zðTÞ have differed. We use new simulations on the Janus II computer to resolve this discrepancy, finding a time-dependent zðT; twÞ, which leads to the experimental value through mild extrapolations. Furthermore, theoretical insight is gained by studying a crossover between the T ¼ Tc and T ¼ 0 fixed points.Item Instanton-like contributions to the dynamics of Yang-Mills fields on the twisted torus(1993) García Pérez, M.; González Arroyo, A.; Martínez, P.; Fernández Pérez, Luis Antonio; Muñoz Sudupe, Antonio; Ruiz Lorenzo, J. J.; Azcoiti, V.; Campos, I.; Ciria, J.C.; Cruz, A.; Íñiguez, D.; Lesmes, F.; Badoni, D.; Pech, J.We study SU(2) lattice gauge theory in small volumes and with twist m ⃗ = (1, 1, 1). We investigate the presence of the periodic instantons of Q = 1/2 and determine their free energy and their contribution to the splitting of energy flux sectors E(e ⃗ = (1, 1, 1)) − E(e ⃗ = (0, 0, 0)).Item Spin-glass dynamics in the presence of a magnetic field: exploration of microscopic properties(Journal of statistical mechanics: theory and experiment, 2021) Paga, I.; Zhai, Q.; Baity-Jesi, M.; Calore, E.; Cruz, A.; Fernández Pérez, Luis Antonio; Gil-Narvión, J. M.; González-Adalid Pemartín, Isidoro; Gordillo Guerrero, A.; Iñiguez, D.; Maiorano, A.; Marinari, E.; Martín Mayor, Víctor; Moreno Gordo, J.; Muñoz Sudupe, Antonio; Navarro, D.; Orbach, R. L.; Parisi, G.; Perez-Gaviro, S.; Ricci-Tersenghi, F.; Ruiz-Lorenzo, J. J.; Schifano, S. F.; Schlagel, D. L.; Seoane Bartolomé, Beatriz; Tarancón, A.; Tripiccione, R.; Yllanes, D.The synergy between experiment, theory, and simulations enables a microscopic analysis of spin-glass dynamics in a magnetic field in the vicinity of and below the spin-glass transition temperature T-g. The spin-glass correlation length, xi(t, t(w); T), is analysed both in experiments and in simulations in terms of the waiting time t(w) after the spin glass has been cooled down to a stabilised measuring temperature T < T-g and of the time t after the magnetic field is changed. This correlation length is extracted experimentally for a CuMn 6 at. % single crystal, as well as for simulations on the Janus II special-purpose supercomputer, the latter with time and length scales comparable to experiment. The non-linear magnetic susceptibility is reported from experiment and simulations, using xi(t, t(w); T) as the scaling variable. Previous experiments are reanalysed, and disagreements about the nature of the Zeeman energy are resolved. The growth of the spin-glass magnetisation in zero-field magnetisation experiments, M-ZFC(t, t(w); T), is measured from simulations, verifying the scaling relationships in the dynamical or non-equilibrium regime. Our preliminary search for the de Almeida-Thouless line in D = 3 is discussed.Item Temperature chaos is present in off-equilibrium spin-glass dynamics(Communications physics, 2021) Fernández Pérez, Luis Antonio; González-Adalid Pemartín, Isidoro; Martín Mayor, Víctor; Muñoz Sudupe, Antonio; Seoane Bartolomé, Beatriz; otros, ...Experiments featuring non-equilibrium glassy dynamics under temperature changes still await interpretation. There is a widespread feeling that temperature chaos (an extreme sensitivity of the glass to temperature changes) should play a major role but, up to now, this phenomenon has been investigated solely under equilibrium conditions. In fact, the very existence of a chaotic effect in the non-equilibrium dynamics is yet to be established. In this article, we tackle this problem through a large simulation of the 3D Edwards-Anderson model, carried out on the Janus II supercomputer. We find a dynamic effect that closely parallels equilibrium temperature chaos. This dynamic temperature-chaos effect is spatially heterogeneous to a large degree and turns out to be controlled by the spin-glass coherence length xi. Indeed, an emerging length-scale xi* rules the crossover from weak (at xi MUCH LESS-THAN xi*) to strong chaos (xi >> xi*). Extrapolations of xi* to relevant experimental conditions are provided. While temperature chaos is an equilibrium notion that denotes the extreme fragility of the glassy phase with respect to temperature changes, it remains unclear whether it is present in non-equilibrium dynamics. Here the authors use the Janus II supercomputer to prove the existence of dynamic temperature chaos, a nonequilibrium phenomenon that closely mimics equilibrium temperature chaos.Item Finite Size Scaling and "perfect" actions: the three dimensional Ising model(Physics letters B, 1998) Ballesteros, H.G.; Fernández Pérez, Luis Antonio; Martín Mayor, Víctor; Muñoz Sudupe, AntonioUsing Finite-Size Scaling techniques, we numerically show that the first irrelevant operator of the lattice λΦ^(4) theory in three dimensions is within errors completely decoupled at λ = 1.0. This interesting result also holds in the Thermodynamical Limit, where the renormalized coupling constant shows an extraordinary reduction of the scaling-corrections when compared with the Ising model. It is argued that Finite-Size Scaling analysis can be a competitive method for finding improved actions.Item The Coulomb-Higgs transition of the three-parameter U(1)-Higgs model(Nuclear Physics B-Proceedings Supplements, 1995) Cruz, A.; Íñiguez, D.; Tarancón, A.; Fernández Pérez, Luis Antonio; Muñoz Sudupe, AntonioWe find a first order Coulomb-Higgs phase transition at moderately large values of the coupling λ, and no evidence for a change of order at any finite value of it.Item The three-dimensional Ising spin glass in an external magnetic field: the role of the silent majority(Journal of statistical mechanics : theory and experiment, 2014) Baity Jesi, Marco; Fernández Pérez, Luis Antonio; Martín Mayor, Víctor; Muñoz Sudupe, AntonioWe perform equilibrium parallel-tempering simulations of the 3D Ising Edwards-Anderson spin glass in a field, using the Janus computer. A traditional analysis shows no signs of a phase transition. Yet, we encounter dramatic fluctuations in the behaviour of the model: Averages over all the data only describe the behaviour of a small fraction of it. Therefore we develop a new approach to study the equilibrium behaviour of the system, by classifying the measurements as a function of a conditioning variate. We propose a finite-size scaling analysis based on the probability distribution function of the conditioning variate, which may accelerate the convergence to the thermodynamic limit. In this way, we find a non-trivial spectrum of behaviours, where a part of the measurements behaves as the average, while the majority of them shows signs of scale invariance. As a result, we can estimate the temperature interval where the phase transition in a field ought to lie, if it exists. Although this would be critical regime is unreachable with present resources, the numerical challenge is finally well posed.Item Nature of the spin-glass phase at experimental length scales(Journal of statistical mechanics: theory and experiment, 2010) Fernández Pérez, Luis Antonio; Martín Mayor, Víctor; Muñoz Sudupe, Antonio; otros, ...We present a massive equilibrium simulation of the three-dimensional Ising spin glass at low temperatures. The Janus special-purpose computer has allowed us to equilibrate, using parallel tempering, L = 32 lattices down to T ≈ 0.64Tc. We demonstrate the relevance of equilibrium finite-size simulations to understand experimental non-equilibrium spin glasses in the thermodynamical limit by establishing a time-length dictionary. We conclude that non-equilibrium experiments performed on a time scale of one hour can be matched with equilibrium results on L ≈ 110 lattices. A detailed investigation of the probability distribution functions of the spin and link overlap, as well as of their correlation functions, shows that Replica Symmetry Breaking is the appropriate theoretical framework for the physically relevant length scales. Besides, we improve over existing methodologies to ensure equilibration in parallel tempering simulations.Item Critical behavior in the site-diluted three-dimensional three-state Potts model(Physical review B, 2000) Ballesteros, H. G.; Fernández Pérez, Luis Antonio; Martín Mayor, Víctor; Muñoz Sudupe, Antonio; Parisi, G.; Ruiz Lorenzo, J. J.We have studied numerically the effect of quenched site dilution on a weak first-order phase transition in three dimensions. We have simulated the site diluted three-states Potts model studying in detail the secondorder region of its phase diagram. We have found that the n exponent is compatible with the one of the three-dimensional diluted Ising model, whereas the h exponent is definitely different.Item Study of the Coulomb-Higgs transition in the abelian Higgs model(Physics letters B, 1998) Cruz, A.; Íñiguez, D.; Fernández Pérez, Luis Antonio; Muñoz Sudupe, Antonio; Tarancón, A.The order of the Coulomb-Higgs transition in the U (1) -Higgs model with unfrozen modulus of the scalar field is studied. Large lattices (up to 24^4 in one case) and high statistics are used. We fix β = 1.15 and explore specially a region of λ-values where metastability is observed. We study the thermodynamical limit of several observables, in particular, the latent heat, the specific heat, the decrement of the free energy between the maxima and the central minimum of the two-peaked histogram, the Binder cumulant and the displacement of the critical coupling with the lattice size. The results point towards a second order transition for λ ≥ 0.005, while for smaller values of λ the strong metastability growing with the lattice size seems to derive from a first order character.