# Enhanced skyrmion stability due to exchange frustration

## TL;DR

This paper shows that considering exchange interactions beyond nearest neighbors is crucial for accurately predicting skyrmion stability, lifetime, and collapse behavior in magnetic systems, highlighting the role of exchange frustration.

## Contribution

It demonstrates that exchange frustration significantly enhances skyrmion stability, which is not captured by simple nearest-neighbor models, providing new insights into skyrmion energetics.

## Key findings

- Exchange interactions beyond nearest neighbors are essential for accurate stability predictions.
- Energy barriers and skyrmion lifetimes are underestimated by simple models.
- Exchange frustration can stabilize skyrmions even in ferromagnetic systems.

## Abstract

Skyrmions are localized, topologically non-trivial spin structures which have raised high hopes for future spintronic applications. A key issue is skyrmion stability with respect to annihilation into the ferromagnetic state. Energy barriers for this collapse have been calculated taking only nearest neighbor exchange interactions into account. Here, we demonstrate that exchange interactions beyond nearest neighbors can be essential to describe stability of skyrmionic spin structures. We focus on the prototypical film system Pd/Fe/Ir(111) and demonstrate that an effective nearest-neighbor exchange or micromagnetic model can only account for equilibrium properties such as the skyrmion profile or the zero temperature phase diagram. However, energy barriers and critical fields of skyrmion collapse as well as skyrmion lifetimes are drastically underestimated since the energy of the transition state cannot be accurately described. Antiskyrmions are not even metastable. Our work shows that frustration of exchange interactions is a route towards enhanced skyrmion stability even in systems with a ferromagnetic ground state.