The Ising model in the presence of a random field is investigated within the mean field approximation based on Landau expansion. The random field is drawn from the asymmetric and anisotropic bimodal probability distribution P(hi)=pδ(hi−h0)+qδ(hi+λ∗h0), where the site probabilities p,q...

We present a conjecture on the exact location of the multicritical point of models of spin glasses on the two-dimensional square lattice using duality transformation. The results not only agree very well with numerical estimates but also conform excellently to the existing knowledge on annealed...

We investigate the two-dimensional ferromagnetic Ising model in the Voronoi–Delaunay tesselation. In this study, we assume that the coupling factor J varies with the distance r between the first neighbors as J(r)∝e−αr, with α⩾0. The disordered system is simulated applying the...

The Ising model in the presence of a random field, drawn from the asymmetric and anisotropic trimodal probability distribution P(hi)=pδ(hi−h0)+qδ(hi+λ∗h0)+rδ(hi), is investigated. The partial probabilities p,q,r take on values within the interval [0,1] consistent with the constraint...

The Ising model in the presence of a random field is investigated within the mean field approximation based on Landau expansion. The random field is drawn from the trimodal probability distribution P(hi)=pδ(hi−h0)+qδ(hi+h0)+rδ(hi), where the probabilities p,q,r take on values within the...

The Ising model, in the presence of a random field, is investigated within the mean-field approximation based on Landau expansion. The random field is drawn from the bimodal probability distribution P(h)=pδ(h−h0)+(1−p)δ(h+h0), where the probability p assumes any value within the interval...

Motivated by spintronic device applications, we engineer a superlattice model based on periodic tri-layers consisting of spins σ=12, S=1 and q=32 residing on the sites of a square lattice, interacting with an external magnetic field. We study its phase diagrams and magnetic properties. We...