  Chiral magnets with the Dzyaloshinskii-Moriya (DM) interaction have received
quite an intensive focus in condensed matter physics because of the presence of
a chiral soliton lattice (CSL), an array of magnetic domain walls and
anti-domain walls, and magnetic skyrmions. In this paper, we realize chiral
magnets in type-IIA/B string theory by using the Hanany-Witten brane
configuration (consisting of D3, D5 and NS5-branes) and the fractional D2 and
D6 branes on the Eguchi-Hanson manifold. In the both cases, we put constant
non-Abelian magnetic fluxes on flavor D-branes, turning them into magnetized
D-branes. The $O(3)$ sigma model with an easy-axis or easy-plane potential and
the DM interaction is realized on the worldvolume of the color D-branes. The
ground state is the ferromagnetic (uniform) phase and the color D-brane is
straight when the DM interaction is small compared with the scalar mass.
However, when the DM interaction is larger, the uniform state is no longer
stable and the ground state is inhomogeneous: the CSL phases and helimagnetic
phase. In this case, the color D-brane is no longer straight but is snaky
(zigzag) when the DM interaction is smaller (larger) than a critical value. A
magnetic domain wall in the ferromagnetic phase is realized as a kinky D-brane.
We further construct magnetic skyrmions in the ferromagnetic phase, realized as
D1-branes (fractional D0-branes) in the former (latter) configuration. We see
that the host D2-brane is bent around the position of a D0-brane as a magnetic
skyrmion. Finally, we construct, in the ferromagnetic phase, domain-wall
skyrmions, that is, composite states of a domain wall and skyrmions, and find
that the domain wall is no longer flat in the vicinity of the skyrmion.
Consequently, a kinky D2-brane worldvolume is pulled or pushed in the vicinity
of the D0-brane depending on the sign of the skyrmion topological charge.
