Effect of nonlinear magnon interactions on the stochastic magnetization switching

TL;DR

This paper investigates how nonlinear magnon interactions, especially four-magnon scatterings, influence stochastic magnetization switching, revealing that these nonlinearities can reduce fluctuations and affect switching frequencies in magnetic devices used for probabilistic computing.

Contribution

It introduces a theoretical analysis of nonlinear magnon interactions, showing their impact on magnetization fluctuations and switching behavior, which was not accounted for in previous linear models.

Findings

Nonlinear four-magnon scatterings reduce magnetization fluctuation amplitudes.

These nonlinearities decrease switching frequencies between magnetic states.

Suppressing effective temperature or device size enhances switching performance.

Abstract

Telegraph noise caused by frequent switching of the magnetization in small magnetic devices has become a useful resource for probabilistic computing. Conventional theories have been based on a linearization of the fluctuations at the extrema of the magnetic free energy. We show theoretically that the non-linearities, specifically four-magnon scatterings, reduce the equilibrium fluctuation amplitude of the magnetization as well as the switching frequencies between local minima via the decay of the homogeneous Kittel mode into two spin waves with opposite momenta. Selectively suppressing the effective temperature of the finite-k spin waves, or reducing the radius of a thin magnetic disk enhance the switching frequency and improve performance of magnetic tunnel junctions in probabilistic computing applications.