arXiv subjects

Justo Rojas Tapia

Publications and source records attributed to Justo Rojas Tapia.

2 recordsLinked to original sources

arXiv2018

Ferromagnetic phases due to competing short- and long-range interactions in the spin-S Blume-Capel model

We broaden the study of the statistical physics of the spin-$S$ Blume-Capel model with ferromagnetic mean-field interactions $J$ in competition with short-range antiferromagnetic interactions $K$ in a linear chain in the thermodynamic limit. This work describes the critical behavior of the model when the $S$ takes a half integer and an integer value. In both cases the phase diagrams exhibit new ferromagnetic phases (for certain values of $K$) enclosed by branches emerging from the first-order frontiers of the pure ferromagnetic model. For finite temperatures the complex topologies were obtained by numerical minimization of the free energy.

cond-mat.stat-mech↗

arXiv2009

Multicriticality in the Blume-Capel model under a continuous-field probability distribution

The multicritical behavior of the Blume-Capel model with infinite-range interactions is investigated by introducing quenched disorder in the crystal field $Δ_{i}$, which is represented by a superposition of two Gaussian distributions with the same width $σ$, centered at $Δ_{i} = Δ$ and $Δ_{i} = 0$, with probabilities $p$ and $(1-p)$, respectively. A rich variety of phase diagrams is presented, and their distinct topologies are shown for different values of $σ$ and $p$. The tricritical behavior is analyzed through the existence of fourth-order critical points as well as how the complexity of the phase diagrams is reduced by the strength of the disorder.

cond-mat.stat-mech↗