Resolution-dependent mechanisms for bimodal switching-time distributions in simulated Fe nanopillars

TL;DR

This study investigates how different computational resolutions affect the bimodal switching-time distributions in simulated iron nanopillars, emphasizing the importance of model accuracy for reliable magnetization dynamics predictions.

Contribution

It demonstrates that the resolution of the computational lattice critically influences the observed switching-time distributions in nanopillar simulations, highlighting the need for appropriate model scaling.

Findings

Different lattice resolutions produce distinct bimodal switching-time behaviors.

Fluctuations leading to bimodality depend on the model resolution.

Correct model resolution is essential for accurate simulation results.

Abstract

We study the magnetization-switching statistics following reversal of the applied field for three separate computational models representing the same physical system, an iron nanopillar. The primary difference between the models is the resolution of the computational lattice and, consequently, the intrinsic parameters that must be rescaled to retain similarity to the physical system. Considering the first-passage time to zero for the magnetization component in the longitudinal (easy-axis) direction, we look for applied fields that result in bimodal distributions of this time for each system and compare the results to the experimental system. We observe that the relevant fluctuations leading to bimodal distributions are different for each lattice resolution and result in magnetization-switching behavior that is unique to each computational model. Correct model resolution is thus essential for obtaining reliable numerical results for the system dynamics.