Spin-orbit torque switching in a single (Ga,Mn)(As,P) layer with perpendicular magnetic anisotropy

초록

We report the observation of current induced spin-orbit torque (SOT) switching of magnetization in a (Ga,Mn)(As,P) film using perpendicular magnetic anisotropy. Complete SOT switching of magnetization was achieved with current densities as low as 7.4 x 10(5) A/cm(2), which is one to two orders of magnitude smaller than that normally used for SOT switching in ferromagnet/heavy metal bilayer systems. The observed magnetization switching chirality during current scans is consistent with SOT arising from spin polarization caused by the Dresselhaus-type spin-orbit-induced (SOI) fields. The magnitudes of effective SOI fields corresponding to the SOT were obtained from shifts of switching angles in angular dependent Hall measurements observed for opposite current polarities. By measuring effective SOI fields for the [110] and the [110] current directions, we were then able to separate the values of the Dresselhaus-type (HeffD) and Rashba (H-eff(R)) SOI fields. At a current density of 6.0 x 10(5) A/cm(2), these values are H-eff degrees D=6.73Oe and H-eff(R)=1.31Oe, respectively. The observed ratio of about 5:1 between Dresselhaus-type and Rashba SOI fields is similar to that observed in a GaMnAs film with an in-plane magnetic anisotropy.