Dynamic-Symmetry-Breaking Breathing and Spreading Transitions in Ferromagnetic Film Irradiated by Spherical Electromagnetic Wave

TL;DR

This study uses Monte Carlo simulations to explore how a ferromagnetic film responds dynamically to a spherical electromagnetic wave, revealing distinct phase transitions and a comprehensive phase diagram.

Contribution

It introduces the first detailed analysis of symmetry-breaking breathing and spreading transitions in ferromagnetic films under spherical EM wave irradiation.

Findings

Identified three dynamic modes: pinned, breathing, and spreading.

Observed nonequilibrium phase transitions and determined their transition temperatures.

Mapped the phase diagram showing merging of transitions at zero field amplitude.

Abstract

The dynamical responses of a ferromagnetic film to a propagating spherical electromagnetic wave passing through it are studied by Monte Carlo simulation of two dimensional Ising ferromagnet. For a fixed set of values of the frequency and wavelength of the spherical EM wave, and depending on the values of amplitude of the EM wave and temperature of the system, three different modes are identified. The static pinned mode, the localised dynamical breathing mode and extended dynamical spreading mode are observed. The nonequilibrium dynamical-symmetry-breaking breathing and spreading phase transitions are also observed and the transition temperatures are obtained as functions of the amplitude of the magnetic field of EM wave. A comprehensive phase diagram is drawn. The boundaries of breathing and spreading transitions merge eventually at the equilibrium transition temperature for two dimensional Ising ferromagnet as the value of the amplitude of the magnetic field becomes vanishingly small.