Objective
The objective of this project is the study of equilibrium and nonequilibrium models of magnetic systems which incorporate some sort of microscopic disorder.
On the first line of the study, the critical behaviour of the magnetic model system usually identified as a fully frustrated classical XY antiferromagnet in a 2-dimensional lattice, with domain second nearest neighbour interactions has been simulated in a computer by the Monte Carlo method.
Work along the second line has produced 2 series of results. In the first the so called driven diffusive lattice gas systems are discussed as models for fast ionic conductors; the associated hydrodynamic equations and expressions for transport coefficients are derived; and mean field theory, Monte Carlo results and experimental observations are compared. The comparison between model and real behaviours helps to understand some properties of those materials which seem to be characterised by the occurrence of nonequilibrium steady states and phase transitions. The second series of results concern the so called reaction diffusion lattice gas model (ie an interacting particle system out of equilibrium whose microscopic dynamics is a combination of creation annihilation (reaction) or Glauber processes and diffusion or Kawasaki processes).
The third line of research combines the experience and objectives of the other two. That is, the focus of interest is in the study of nonequilibrium steady states, phase transitions and critical phenomena in disordered systems. A simple, systematic method has been developed to investigate the existence of stationary probability distributions for interacting particle or spin lattice systems exhibiting steady nonequilibrium states. In addition, exact results have been found for one and two dimensional lattice Ising like model systems in which competing kinetic process induces the presence of nonequilibrium steady states dominated by a kind of dynamic disorder. The model, which may be relevant in relation to the spin-glass problem, serves also to uncover some novel features of nonequilibrium phase transitions and critical phenomena.
This project is continuing.
Topic(s)
Data not availableCall for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
18071 GRANADA
Spain