  Magnetic skyrmions are promising spin textures for building next-generation
magnetic memories and spintronic devices. Nevertheless, one of the major
challenges in realizing skyrmion-based devices is the stabilization of ordered
arrays of these spin textures in different geometries. Here we numerically
study the skyrmion-skyrmion interaction potential that arises due to the
dynamics of itinerant electrons coupled to the magnetic texture in a
ferromagnetic background with racetrack geometry. We consider different
topological textures (ferromagnetic (FM) and antiferromagnetic (AFM)), namely:
skyrmions, antiskyrmions and biskyrmions. We show that at low electron filling,
for sufficiently short separation, the skyrmions strongly couple each other
yielding a bound-state bound by electronic dynamics. However, when the filling
is increased, the interaction potential energy presents local minima at
specific values of the skyrmion-skyrmion distance. Each of these local minima
correspond to energetically stable positions of skyrmions which are "protected"
by well defined energy barriers. By inspecting the local charge density, we
find that in the case of AFM skyrmions, the local antiferromagnetic nature
prevents electronic penetration into the core, allowing the AFM skyrmions to be
seen as infinite potential barriers for electrons.
