Theory of perpendicular magnetic anisotropy due to surface Rashba spin-orbit interaction and its electric field control

Ieda, Junichi   ; Barnes, S. E.*; Maekawa, Sadamichi

Spin-orbit interaction leads to two competitive interactions, i.e., anisotropic exchange and anti-symmetric exchange interactions. Similarly, surface Rashba spin-orbit interaction gives rise to two effects in ferromagnets: one is prefer to the in-plane magnetic anisotropy while the other yields to the perpendicular magnetic anisotropy, and whether which is dominant depends on the electronic structure of ferromagnets. For the ultra-thin ferromagnetic layers, in particular, the surface Rashba spin-orbit interaction can be controlled by external electric fields and thus it is interesting to investigate electric field dependence of such a magnetic anisotropy. We present this new mechanism of perpendicular magnetic anisotropy.