A trilayer synthetic anti-ferromagnetic structure is set-up with bilinear surface exchange coupling betweeen Ni80Fe20 layers of 10 nm/20 nm/10 nm thickness and 2 nm Ru spacers between layers. The thicker layer initially points to the left and an opposing magnetic field is applied which is not strong enough to overcome the anti-ferromagnetic coupling. The thicker layer switches towards the field but the structure retains an anti-parallel magnetisation configuration. The switching occurs very quickly (~1 ns) but the magnetisation precession continues on a much longer time scale eventually decreasing to zero (the simulation time shown in the clip is only 5 ns).
The three layers are set-up using three separate computational meshes, whilst the demagnetising field is computed on the super-mesh with transfer to/from individual meshes using a smoother (publication on computational procedure to follow).