Dynamic hysteresis for Potts spin system: a Monte Carlo simulation

Abstract.

A Monte Carlo approach based on the Q-state Potts model is developed to describe and simulate the dynamic hysteresis of Potts spin lattice against periodic time-varying external field E. The dynamic responses of the hysteresis loops against frequency ω of applied field and domain size R are studied. It is revealed that the hysteresis loops for the system energy W, polarization P, and domain wall fraction Π depend considerably on the frequency and domain size. The remnant polarization P_r shows a single-peak pattern as a function of ω. The P-E loop exhibits thin rhomb and fat rhomb patterns at low ω, whereas a tip-smoothed rhomb and roughly elliptical pattern is observed at high ω. The loop area can be scaled with Ω≈ω^1/3 at low ω. The frequency dependency of the dynamic hysteresis is explained in terms of a simplified phenomenological model. At very small domain size, the dynamic hysteresis is significantly compressed, predicting the polarization weakening effect at small domain size.