Global persistence exponent of the double-exchange model

Abstract

We obtained the global persistence exponent $θ_g$ for a continuous spin model on the simple cubic lattice with double-exchange interaction by using two different methods. First, we estimated the exponent $θ_g$ by following the time evolution of probability $P(t)$ that the order parameter of the model does not change its sign up to time $t$ $[P(t)\thicksim t^{-θ_g}]$. Afterwards, that exponent was estimated through the scaling collapse of the universal function $L^{θ_g z} P(t)$ for different lattice sizes. Our results for both approaches are in very good agreement each other.