Magnetic skyrmions: topologically protected spin vortices with integer winding number Q
A skyrmion is a topological soliton in a 2D magnetic system — a vortex-like spin texture with a quantized topological charge (winding number).
Skyrmions are stabilized by competing interactions: Heisenberg exchange (J), Dzyaloshinskii-Moriya interaction (D), and external magnetic field (B). The DM interaction arises from broken inversion symmetry and cants neighboring spins.
Skyrmions are topologically protected: Q cannot change continuously — annihilation requires an energy barrier. They are candidates for spintronic memory bits.