Magnetic bit stability: Competition between domain-wall and monodomain switching

TL;DR

This paper investigates the thermal stability of magnetic memory bits, focusing on how domain-wall and monodomain switching mechanisms compete, with implications for improving data retention in magnetic storage devices.

Contribution

It introduces a variational method to analyze energy barriers in magnetic bits, revealing textured configurations that can lower switching energy barriers compared to monodomain states.

Findings

Textured configurations can reduce energy barriers.

Domain-wall propagation influences thermal stability.

Micromagnetic effects differ between thermal and field-induced switching.

Abstract

We numerically study the thermal stability properties of computer memory storage realized by a magnetic ellipse. In the case of practical magnetic random-access memory devices, the bit can form a spin texture during switching events. To study the energy barrier for thermally-induced switching, we develop a variational procedure to force the bit to traverse a smooth path through configuration space between the points of stability. We identify textured configurations realizing domain-wall propagation, which may have an energy barrier less than that of the corresponding monodomain model. We contrast the emergence of such micromagnetic effects in thermal versus field-induced switching.