As an alternative to conventional magnetic field, the effective spin-orbit
field in transition metals, derived from the Rashba field experienced by
itinerant electrons confined in a spatial inversion asymmetric plane through
the s-d exchange interaction, is proposed for the manipulation of
magnetization. Magnetization switching in ferromagnetic thin films with
perpendicular magnetocrystalline anisotropy can be achieved by current induced
spin-orbit field, with small in-plane applied magnetic field. Spin-orbit field
induced by current pulses as short as 10 ps can initiate ultrafast
magnetization switching effectively, with experimentally achievable current
densities. The whole switching process completes in about 100 ps.Comment: 4 pages, 3 figure