Stochastic dynamics and the dynamic phase transition in thin ferromagnetic films

Area of Science:

• Condensed Matter Physics
• Statistical Mechanics
• Computational Physics

Background:

• Investigating dynamic phase transitions (DPT) is crucial for understanding complex magnetic systems.
• Thin film geometries introduce unique surface effects influencing magnetic behavior.
• Classical Heisenberg spin systems with anisotropy exhibit rich phase behaviors.

Purpose of the Study:

• To explore the dynamic phase behavior of a Heisenberg spin system in a thin film.
• To compare the effects of Glauber and Metropolis stochastic dynamics on DPT.
• To analyze the influence of pulsed oscillatory fields and competing surface fields on DPT.

Main Methods:

• Utilized Monte Carlo simulations to model the spin system.
• Employed two distinct stochastic dynamics: Glauber and Metropolis.
• Simulated thin films under pulsed oscillatory external fields with competing surface fields.

Main Results:

• Both Glauber and Metropolis dynamics demonstrated a continuous dynamic phase transition (DPT).
• Field amplitude dependence of DPT was similar for both dynamics.
• Metropolis dynamics exhibited a more extended DPT temperature region compared to Glauber dynamics.

Conclusions:

• The choice of stochastic dynamics significantly impacts the characteristics of DPT in thin films.
• Metropolis dynamics reveal a decoupling of surface and bulk responses near DPT, not observed with Glauber dynamics.
• These findings highlight the importance of selecting appropriate simulation methods for studying dynamic phenomena in magnetic thin films.