Ising Metamagnet Driven by Propagating Magnetic Field Wave: Nonequilibrium Phases and Transitions

TL;DR

This study uses Monte Carlo simulations to explore how a propagating magnetic wave influences the nonequilibrium phases and transitions of an Ising metamagnet, revealing dynamic symmetry breaking and complex phase behavior.

Contribution

It provides the first detailed analysis of nonequilibrium phase transitions in an Ising metamagnet driven by a propagating magnetic wave, including phase diagrams and transition characteristics.

Findings

Low amplitude fields induce a single phase transition with sharp specific heat peak.

High amplitude fields cause multiple phase transitions in the system.

Transition behavior approaches equilibrium ferromagnetic transition as wave amplitude vanishes.

Abstract

The nonequilibrium responses of Ising metamagnet (layered antiferromagnet) to the propagating magnetic wave are studied by Monte Carlo simulation. Here, the spatio-temporal variations of magnetic field keeps the system away from equilibrium. The sublattice magnetisations show dynamical symmetry breaking in the low temperature ordered phase. The nonequilibrium phase transitions are studied from the temperature dependences of dynamic staggered order parameter, its derivative and the dynamic specific heat. The transitions are marked by the peak position of dynamic specific heat and the position of dip of the derivative of dynamic staggered order parameter. It is observed that, for lower values of the amplitudes of the propagating magnetic field, if the system is cooled from a high temperature, it undergoes a phase transition showing sharp peak of dynamic specific heat and sharp dip of the derivative of the dynamic staggered order parameter. However, for higher values of the amplitude of the propagating magnetic field, system exhibits multiple phase transitions. A comprehensive phase diagram is also plotted. The transition, for vanishingly small value of the amplitude of the propagating wave, is very close to that for equilibrium ferro-para phase transition of cubic Ising ferromagnet.