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M. L. Rubio Puzzo

Publications and source records attributed to M. L. Rubio Puzzo.

2 recordsLinked to original sources

Dynamic behavior of a magnetic system driven by an oscillatory external temperature

The dynamic effects on a magnetic system exposed to a time-oscillating external temperature are studied using Monte Carlo simulations on the classic 2D Ising Model. The time dependence of temperature is defined as $T(t)=T_0 + A \cdot \sin(2πt/τ)$. Magnetization $M(t)$ and period-averaged magnetization $\langle Q\rangle$ are analyzed to characterize out-of-equilibrium phenomena. Hysteresis-like loops in $M(t)$ are observed as a function of $T(t)$. The area of the loops is well-defined outside the critical Ising temperature ($T_c$) but takes more time to close it when the system crosses the critical curve. Results show a power-law dependence of $\langle Q\rangle$ (the averaged area of loops) on both $L$ and $τ$, with exponents $α=1.0(1)$ and $β=0.70(1)$, respectively. Furthermore, the impact of shifting the initial temperature $T_0$ on $\langle Q\rangle$ is analyzed, suggesting the existence of an effective $τ$-dependent critical temperature $T_c(τ)$. A scaling law behavior for $\langle Q\rangle$ is found on the base of this $τ$-dependent critical temperature.

cond-mat.stat-mech

Griffiths-like phase in the three-dimensional $\pm J$ Edwards-Anderson spin-glass model

Using information of the ground state topology and the damage spreading technique we show a Griffiths-like phase is present in the three-dimensional $\pm J$ Edwards-Anderson spin glass model. With spin-flipping dynamics damage spreads for temperatures larger than $T_{\mathrm{g}}$, the glass transition temperature. With spin-orienting dynamics and for temperatures in $T_{\mathrm{g}} < T < T_{\mathrm{d}}$, damage spreads over a finite region of the system, composed of finite clusters of ferromagnetic character. $T_{\mathrm{d}}$ is the spin-orienting damage critical temperature, which is of the same order as the critical temperature of the ferromagnetic Ising model, $T_{\mathrm{c}}$. The present results allow us to identify the clusters which originate the Griffiths-like phase in the present model.

cond-mat.stat-mech