Polarised Electromagnetic wave propagation through the ferromagnet: Phase boundary of dynamic phase transition

TL;DR

This study models the dynamic phase transition in a 2D Ising ferromagnet under a propagating electromagnetic wave, revealing phase boundaries and the effects of wave speed on the transition.

Contribution

It introduces a Monte Carlo simulation approach to analyze the phase boundary of dynamic transitions in ferromagnets under electromagnetic waves.

Findings

Dynamic phase transition depends on temperature and field amplitude.

Phase boundary shrinks with decreasing wave propagation speed.

Divergence of length scale observed at transition point.

Abstract

The dynamical responses of ferromagnet to the propagating electromagnetic field wave passing through it are modelled and studied here by Monte Carlo simulation in two dimensional Ising ferromagnet. Here, the electromagnetic wave is linearly polarised in such a way that the direction of magnetic field is parallel to that of the magnetic momemts (spins). The coherent propagating mode of spin-clusters is observed. The time average magnetisation over the full cycle (time) of the field defines the order parameter of the dynamic transition. Depending on the value of the temperature and the amplitude of the propagating magnetic field wave, a dynamical phase transition is observed. The dynamic transition was detected by studying the temperature dependences of the dynamic order parameter, the variance of the dynamic order parameter, the derivative of the dynamic order parameter and the dynamic specific heat. The phase boundaries of the dynamic transitions were drawn for two different values of the wave lengths of the propagating magnetic field wave. The phase boundary was observed to shrink (inward) for lower speed of propagation of the EM wave. The divergence of the releavant length scale was observed at the transition point.