Fig. 1: Zero field skyrmion motion.

Skyrmion motion was observed in a 2 µm wide Ta(3.2)/Pt(2.7)/[CoB (0.8)/Ir (0.4)/Pt (0.6)]_×5/Pt (2.2) multilayer wire (thickness in nm) in 0 mT applied field. a Magnetisation, M_x, versus in-plane (μ₀H_x) and normalised magnetisation M_zM⁻¹_S versus out-of-plane (μ₀H_z) field measured on a multilayer film using SQUID vibrating sample magnetometry and MOKE magnetometry. The saturation magnetisation, M_S was measured to be 1.2 ± 0.1 MAm⁻¹. b Brillouin light scattering was used to measure the DMI strength, D, of a multilayer film. D was extracted from the asymmetry of the Stokes and anti-Stokes lines due to inelastically scattering of the incident light from the propagating spin waves with magnon wavevector, and was found to be −1.1 ± 0.1 mJm⁻². c Time-trace of a positive (red) and negative (blue) current pulse applied through the wire. d–i Single helicity STXM images after two consecutive 9-ns-long current pulses with current densities of J = 1.2 × 10¹² Am⁻² applied along the direction of the red arrow (positive current) and j–o along the blue arrow (negative current). The dashed lines track the vertical position of the skyrmion centre throughout the pulse sequence. An average skyrmion velocity of 8 ± 3 ms⁻¹ was observed in this sequence of images.