Patent ID: 8729648

Claim:
A magnetic body device comprising: an underlying layer; a cap layer formed of a material different from that of the underlying layer; a magnetic body layer in contact at the lower surface with the underlying layer and in contact at the upper surface with the cap layer; and a pair of current terminals for supplying a current to the underlying layer and the magnetic body layer, wherein the magnetic body layer has a free magnetization region having a perpendicular magnetic anisotropy and a first characteristic change region and a second characteristic change region situated on both sides of the free magnetization region in a first in-plane direction, perpendicular magnetic anisotropy of the first characteristic change region and the second characteristic change region is lower than that of the free magnetization region, an external magnetic field containing a component in the first-plane direction is applied to the free magnetization region, the underlying layer has a first underlying region in contact with the lower surface of the first characteristic change region and a second underlying region in contact with the lower surface of the second characteristic change region, and the pair of current terminals is coupled to the first underlying region and the second underlying region respectively.