Multiple dynamic transitions in anisotropic Heisenberg ferromagnet driven by polarised magnetic field

Uniaxially (Z-axis) anisotropic Heisenberg ferromagnet, in presence of time dependent (but uniform over space) magnetic field, is studied by Monte Carlo simulation. The time dependent magnetic field was taken as elliptically polarised where the resultant field vector rotates in X-Z plane. The system is cooled (in presence of the elliptically polarised magnetic field) from high temperature. As the temperature decreases, it was found that in the low anisotropy limit the system undergoes three successive dynamical phase transitions. These three dynamic transitions were confirmed by studying the temperature variation of dynamic 'specific heat'. The temperature variation of dynamic 'specific heat' shows three peaks indicating three dynamic transition points.