Stability and asymptotic interactions of chiral magnetic skyrmions in a tilted magnetic field

Abstract

Using a general framework, interaction potentials between chiral magnetic solitons in a planar system with a tilted external magnetic field are calculated analytically in the limit of large separation. The results are compared to previous numerical results for solitons with topological charge $\pm 1$. A key feature of the calculation is the interpretation of Dzyaloshinskii-Moriya interaction (DMI) as a background $SO(3)$ gauge field. In a tilted field, this leads to a $U(1)$-gauged version of the usual equation for spin excitations, leading to a distinctive oscillating interaction profile. We also obtain predictions for skyrmion stability in a tilted field which closely match numerical observations.Comment: Updated to the final version published in SciPost Physics. Small change to notation to distinguish between the abstract gauge field $\boldsymbol{A}_i$ and the concrete DMI parameters of a given magnet $\boldsymbol{D}_i$. No other significant change