36 citations · 150 across the 11 of their papers we have counts for
11 papers
The random field Blume-Capel model revisited
P. V. Santos, F. A. da Costa, J. M. de Araújo
We have revisited the mean-field treatment for the Blume-Capel model under the presence of a discrete random magnetic field as introduced by Kaufman and Kanner. The magnetic field…
Noise induced phase transition in the -state block voter model
J. M. de Araújo, C. I. N. Sampaio Filho, F. G. B. Moreira
We use Monte Carlo simulations and finite-size scaling theory to investigate the phase transition and critical behavior of the -state block voter model on square lattices. It is…
Mean field solution of the Blume-Capel model under a random crystal field
P. V. Santos, F. A. Costa, J. M. Araújo
In this work we investigate the Blume-Capel model with infinite-range ferromagnetic interactions and under the influence of a quenched disorder - a random crystal field. For a suit…
Chaotic behavior of a spin-glass model on a Cayley tree
F. A. da Costa, J. M. de Araujo, S. R. Salinas
We investigate the phase diagram of a spin--1 Ising spin-glass model on a Cayley tree. According to early work of Thompson and collaborators, this problem can be formulated in term…
The anisotropic Ashkin-Teller model: a renormalization group study
C. G. Bezerra, A. M. Mariz, J. M. de Araujo +1
The two-dimensional ferromagnetic anisotropic Ashkin-Teller model is investigated through a real-space renormalization-group approach. The critical frontier, separating five distin…
Magnetization in quasiperiodic magnetic multilayers with biquadratic exchange coupling
C. G. Bezerra, J. M. de Araujo, C. Chesman +1
A theoretical study of the magnetization curves of quasiperiodic magnetic multilayers is presented. We consider structures composed by ferromagnetic films (Fe) with interfilm excha…
Tricritical Points in the Sherrington-Kirkpatrick Model in the Presence of Discrete Random Fields
J. M. de Araujo, F. D. Nobre, F. A. da Costa
The infinite-range-interaction Ising spin glass is considered in the presence of an external random magnetic field following a trimodal (three-peak) distribution. The model is stud…
Zero-temperature TAP equations for the Ghatak-Sherrington model
F. A. da Costa, J. M. de Araujo
The zero-temperature TAP equations for the spin-1 Ghatak-Sherrington model are investigated. The spin-glass energy density (ground state) is determined as a function of the anisotr…
Effects of Random Biquadratic Couplings in a Spin-1 Spin-Glass Model
J. M. de Araujo, F. A. da Costa, F. D. Nobre
A spin-1 model, appropriated to study the competition between bilinear (J_{ij}S_{i}S_{j}) and biquadratic (K_{ij}S_{i}^{2}S_{j}^{2}) random interactions, both of them with zero mea…
First-order transitions and triple point on a random p-spin interaction model
J. M. de Araujo, F. A. da Costa, F. D. Nobre
The effects of competing quadrupolar- and spin-glass orderings are investigated on a spin-1 Ising model with infinite-range random -spin interactions. The model is studied throu…
Self-similar magnetoresistance of Fibonacci ultrathin magnetic films
C. G. Bezerra, J. M. de Araujo, C. Chesman +1
We study numerically the magnetic properties (magnetization and magnetoresistance) of ultra-thin magnetic films (Fe/Cr) grown following the Fibonacci sequence. We use a phenomenolo…