Transition metal synthetic ferrimagnets: tuneable media for all-optical switching driven by nanoscale spin current by Dabrowski, M, Scott, JN, Hendren, WR, Forbes, CM, Frisk, A, Burn, DM, Newman, DG, Sait, CRJ, Keatley, PS, N'Diaye, AT, Hesjedal, T, van der Laan, G, Bowman, RM, Hicken, RJ