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 classical 2D Ising Model. The time dependence of temperature is defined as T (t) = T 0 + A ⋅ sin (2 π t ∕ τ). Magnetization M (t) and period-averaged magnetization 〈 Q 〉 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 〈 Q 〉 (the averaged area of loops) on both L and τ , with exponents α = 1. 0 (1) and β = 0. 7 0 (1) , respectively. Furthermore, the impact of shifting the initial temperature T 0 on 〈 Q 〉 is analyzed, suggesting the existence of a τ -dependent effective temperature T eff (τ). A scaling law behavior for 〈 Q 〉 is found on the base of this τ -dependent temperature. [ABSTRACT FROM AUTHOR]