Monte Carlo Simulation with Time Step Quantification in Terms of Langevin Dynamics

Abstract

For the description of thermally activated dynamics in systems of classical magnetic moments numerical methods are desirable. We consider a simple model for isolated magnetic particles in a uniform field with an oblique angle to the easy axis of the particles. For this model, a comparison of the Monte Carlo method with Langevin dynamics yields new insight to the interpretation of the Monte Carlo process, leading to the implementation of a new algorithm where the Monte Carlo step is time quantified. The numeric results for the characteristic time of the magnetization reversal are in excellent agreement with asymptotic solutions for the Néel-Brown model.