As shown in FIG. 6B, the first spin Hall layer 252 comprises a heavy metal material having a positive spin Hall angle, such as platinum, while the second spin Hall layer 253 comprises a heavy metal material having a negative spin Hall angle, such as beta phase tungsten (β-W) or beta phase tantalum (β-Ta). The charge current through the first spin Hall layer 252 generates a spin current 292 at the surface of the first spin Hall layer 252 with a magnetization direction down 292D proximate the first side 271-1 and the second side 271-2 of the STL 271 and a magnetization direction up 292U away from the first side 271-1 and the second side 271-2 of the STL 271 due to the positive spin Hall angle of the first spin Hall layer 252. The charge current through the second spin Hall layer 253 generates a spin current 293 at the surface of the second spin Hall layer 253 with a magnetization direction down 293D proximate to the third side 271-3 of the STL 271 and magnetization direction up 293U away from the STL 271 due to the negative spin Hall angle of the second spin Hall layer 253. Since there are three charge current paths as along the first side 271-1, second side 271-2, and third side 271-3 of the STL 271, there are three ampere magnetic fields generated by the flowing charge currents. Not wishing to be bound by theory unless explicitly set forth in the claims, it is believed that the STL 271 experiences less degradation due to being under the influences of three ampere magnetic fields in comparison to one ampere magnetic field.