Baby Skyrmion crystals

This paper describes a model for baby Skyrme crystal chunks with arbitrary potential by considering energy contributions from the bulk and surface of chunk. We focus on two potentials which yield distinct lattices: standard $V={m}^{2}(1\ensuremath{-}{\ensuremath{\varphi}}^{3})$ easy plane $V=\frac{1}{2}{m}^{2}({\ensuremath{\varphi}}^{1}{)}^{2}$. In both models, static functional is minimized over all two-dimensional period lattices, yielding minimal-energy structure(s). For potential, Skyrmions form hexagonal structure, whereas, structure square lattice half-charge lumps. find that are global minima in charges $B>6$, $2B$ being perfect (${m}^{2}=1$). contrast, we observe become surprisingly large charges, $B>954$ (${m}^{2}=0.1$).