Baby skyrmion crystals stabilized by vector mesons

Abstract

In this letter we study soliton crystals in the $(2+1)$-dimensional analogue model of the $(3+1)$-dimensional Adkins--Nappi model of nuclear physics. The baby $\omega$-Skyrme model studied here is an $O(3)$ nonlinear $\sigma$ model coupled to a massive vector meson, the $\omega$-meson. Using recently developed methods in the $(3+1)$-dimensional $\omega$-Skyrme model we are able to construct soliton crystals in this $(2+1)$-dimensional baby $\omega$-Skyrme model. The resulting crystals form a hexagonal lattice structure and are qualitatively and quantitatively similar to crystals observed in the standard baby Skyrme model.