a SEM image of the device (false color). Inset shows a SEM image of a junction groove and a FIB track (for another device). b A sketch of the cell with indicated directions of wordline and bitline currents. c Direction of Lorentz forces, exerted on a vortex and an antivortex by a positive WL current. The easy operation with a small WL threshold current is expected when the vortex is transported along the track.