Multidimensional instability and dynamics of spin-avalanches in crystals of nanomagnets

TL;DR

This paper develops a theory for the instability of magnetization-switching fronts in nanomagnet crystals, revealing complex multidimensional dynamics and universal physical mechanisms shared with other systems like combustion and fusion.

Contribution

It introduces a comprehensive instability theory for spin-avalanches in nanomagnet systems, including both linear and nonlinear stages, supported by numerical simulations.

Findings

Instability causes spontaneous distortion of magnetic fronts.

Results show complex multidimensional front dynamics.

Universal physical nature links to other instability phenomena.

Abstract

We obtain a fundamental instability of the magnetization-switching fronts in super-paramagnetic and ferromagnetic materials such as crystals of nanomagnets, ferromagnetic nanowires, and systems of quantum dots with large spin. We develop the instability theory for both linear and nonlinear stages. By using numerical simulations we investigate the instability properties focusing on spin avalanches in crystals of nanomagnets. The instability distorts spontaneously the fronts and leads to a complex multidimensional front dynamics. We show that the instability has a universal physical nature, with a deep relationship to a wide variety of physical systems, such as the Darrieus-Landau instability of deflagration fronts in combustion, inertial confinement fusion and thermonuclear su- pernovae, and the instability of doping fronts in organic semiconductors.