Figure 5. Vertical-current-driven motion of a skyrmionic bit chain with initial spacing of 30 nm on the 40-nm-wide racetrack at (a) t = 0.4 ns, (b) t = 0.7 ns, and motion of a chain with initial spacing of 60 nm at (c) t = 0.4 ns, (d) t = 0.7 ns.

The current density j = 5 × 10¹⁰ A/m², polarization P = 0.4 and DMI constant D = 3 × 10⁻³ J/m². The direction of the electron polarization m_p is shown in the upper right corner.