A5090317819- Theoretical and Computational Physics
- Complex Systems and Time Series Analysis
- Quantum Chromodynamics and Particle Interactions
- Material Dynamics and Properties
- Complex Network Analysis Techniques
- Physics of Superconductivity and Magnetism
- Particle physics theoretical and experimental studies
- Stochastic processes and statistical mechanics
- High-Energy Particle Collisions Research
- Chronic Lymphocytic Leukemia Research
- Quantum many-body systems
- Advanced Condensed Matter Physics
- Opinion Dynamics and Social Influence
- Magnetic confinement fusion research
- Magnetic and transport properties of perovskites and related materials
- T-cell and B-cell Immunology
- Markov Chains and Monte Carlo Methods
- Ionosphere and magnetosphere dynamics
- Immune Cell Function and Interaction
- Black Holes and Theoretical Physics
- Magnetic properties of thin films
- Monoclonal and Polyclonal Antibodies Research
- Scientific Research and Discoveries
- Blood Pressure and Hypertension Studies
- Parallel Computing and Optimization Techniques
United States Naval Research Laboratory
2025
Instituto de Biocomputación y Física de Sistemas Complejos
2015-2024
Universidad Complutense de Madrid
2014-2024
Hospital Clínico Universitario de Valladolid
2024
Universidad de La Frontera
2023
Universidad de Cádiz
2022
Universidad de Zaragoza
1997-2019
Ateneo de Manila University
2017
Universidad de Cantabria
2015-2016
University of Wisconsin–Madison
2010
We have simulated, using parallel tempering, the three-dimensional Ising spin glass model with binary couplings in a helicoidal geometry. The largest lattice $(L=20)$ has been studied dedicated computer (the SUE machine). obtained, measuring correlation length critical region, strong evidence for second-order finite-temperature phase transition, ruling out other possible scenarios like Kosterlitz-Thouless transition. Precise values \ensuremath{\nu} and \ensuremath{\eta} exponents are also presented.
We study the phase diagram of site-diluted Ising model in a wide dilution range, through Monte Carlo simulations and finite-size scaling techniques. Our results for critical exponents universal cumulants turn out to be independent, but only after proper infinite volume extrapolation, taking into account leading corrections-to-scaling terms.
We report a high-precision finite-size scaling study of the critical behavior three-dimensional Ising Edwards-Anderson model (the spin glass). have thermalized lattices up to L=40 using Janus dedicated computer. Our analysis takes into account leading-order corrections scaling. obtain Tc = 1.1019(29) for temperature, \nu 2.562(42) thermal exponent, \eta -0.3900(36) anomalous dimension and \omega 1.12(10) exponent leading Standard (hyper)scaling relations yield \alpha -5.69(13), \beta...
The Mpemba effect occurs when a hot system cools faster than an initially colder one, both are refrigerated in the same thermal reservoir. Using custom-built supercomputer Janus II, we study spin glasses and show that it is nonequilibrium process, governed by coherence length ξ of system. bath temperature lies glassy phase, but not necessary for protocol to cross critical temperature. In fact, follows from strong relationship between internal energy turns out be sure-tell sign being phase....
Using finite-size scaling techniques we obtain accurate results for critical quantities of the Ising model and site percolation, in three dimensions. We pay special attention to parametrizing corrections-to-scaling, which is necessary bring systematic errors below statistical ones.
We study the behavior of string tension in SU(3) lattice pure-gauge theory close to deconfining critical point. find very large correlation lengths, increasing with size. This result is strongly suggestive a second-order phase transition, and excludes presence strong first-order transition.
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 T ≈ 0.64Tc. demonstrate relevance finite size simulations understanding experimental non-equilibrium glasses in thermodynamical limit by establishing time-length dictionary. conclude that experiments performed on timescale 1 h can be matched with results 110 lattices. A...
We present a tethered Monte Carlo simulation of the crystallization hard spheres. Our method boosts traditional umbrella sampling to point making practical study constrained Gibbs' free energies depending on several crystalline order parameters. obtain high-accuracy estimates fluid-crystal coexistence pressure for up 2916 particles (enough accommodate fluid-solid interfaces). are able extrapolate infinite volume [${p}_{\mathrm{co}}=11.5727(10){k}_{B}T/{\ensuremath{\sigma}}^{3}$] and...
We study numerically the nonequilibrium dynamics of Ising spin glass, for a time spanning 11 orders magnitude, thus approaching experimentally relevant scale (i.e., seconds). introduce novel analysis techniques to compute coherence length in model-independent way. present strong evidence replicon correlator and overlap equivalence. The emerging picture is compatible with noncoarsening behavior.
This paper describes JANUS, a modular massively parallel and reconfigurable FPGA-based computing system. Each JANUS module has computational core host. The is 4x4 array of processing elements with nearest-neighbor data links. Processors are also directly connected to an I/O node attached the host, conventional PC. tailored for, but not limited to, requirements class hard scientific applications characterized by regular code structure, unconventional manipulation instructions too large...
We have investigated the phase transition in Heisenberg spin glass using massive numerical simulations to study very large sizes, ${48}^{3}$. A finite-size scaling analysis indicates that data are compatible with most economical scenario: a common temperature for spins and chiralities.
Spin glasses are a longstanding model for the sluggish dynamics that appears at glass transition. However, spin differ from structural crucial feature: they enjoy time reversal symmetry. This symmetry can be broken by applying an external magnetic field, but embarrassingly little is known about critical behaviour of in field. In this context, space dimension crucial. Simulations easier to interpret large number dimensions, one must work below upper (i.e., d<6) order results have relevance...
We perform equilibrium parallel-tempering simulations of the 3D Ising Edwards-Anderson spin glass in a field. A traditional analysis shows no signs phase transition. Yet, we encounter dramatic fluctuations behaviour model: Averages over all data only describe small fraction it. Therefore develop new approach to study system, by classifying measurements as function conditioning variate. propose finite-size scaling based on probability distribution variate, which may accelerate convergence...
We find a dynamic effect in the non-equilibrium dynamics of spin glass that closely parallels equilibrium temperature chaos. This effect, we name chaos, is spatially heterogeneous to large degree. The key controlling quantity time-growing spin-glass coherence length. Our detailed characterization chaos paves way for analysis recent and forthcoming experiments. work has been made possible thanks most massive simulation date dynamics, carried out on Janus~II custom-built supercomputer.
The phase diagram of the double perovskites type ${\mathrm{Sr}}_{2\ensuremath{-}x}{\mathrm{La}}_{x}{\mathrm{FeMoO}}_{6}$ is analyzed, with and without disorder due to antisites. In addition an homogeneous half metallic ferrimagnetic in absence doping disorder, we find antiferromagnetic phases at large dopings, other lower saturation magnetization, presence disorder.
We study the site-diluted Ising model in two dimensions with Monte Carlo simulations. Using finite-size scaling techniques we compute critical exponents observing deviations from pure ones. The differences can be explained as effects of logarithmic corrections, without requiring us to change universality class.
Evidence indicates that after vascular occlusion, infusion of angiotensin II restores blood supply to ischemic tissues by stimulating the development collateral circulation through a mechanism independent mechanical effects increased pressure. To test this effect in focal cerebral ischemia, was intravenously administered for four hours gerbils immediately unilateral carotid ligation. Three different pressor doses, 50, 250, and 500 ng/kg/min, were used, mortality rate evaluated at 1 2 days...