Revisiting fermion bound states in baby Skyrme background with Dzyaloshinskii Moriya interaction

Abstract

In this paper, we investigate a fermion coupled to a Skyrme model in $2+1$ dimensions, where the Skyrmion is stabilized by the Dzyaloshinskii-Moriya and Skyrme interactions under a quadratic potential. This framework interpolates between the magnetic Skyrmion at the critical coupling and the baby-Skyrme limit. The Dirac equation is studied both analytically in a non-relativistic reduction and numerically for the full relativistic spectrum, and the parameter region admitting states bound to the Skyrmion is determined. Localized solutions exist only for electrically charged fermions with positive charge and negative angular momentum, and are absent for neutral fermions. The lowest bound state in each angular momentum sector is characterized as a function of the fermion mass, charge, and the coupling $h$ to the Skyrmion isospin, and its behavior is compared across the magnetic, baby, and mixed Skyrmion backgrounds. The resulting fermion--Skyrmion composite constitutes an electrically charged state bound to a topological texture, providing concrete signatures for potential future transport and scattering measurements in chiral magnets.