(color online) (a) Schematic illustration of the model system. The polarized currents are applied via three nanocontacts represented by white cylinders with radius . The radius of the Permalloy dot is R = 200 nm and its thickness is L = 10 nm. The magnetization distributions are indicated by the out-of-plane cone and the white arrow, respectively. (b) Critical current density and the corresponding switching time of different current combinations as noted and one nanocontact.