Patent ID: 8675309

Claim:
A spin-torque oscillator (STO) comprising: a substrate; a set of layers on the substrate comprising: a first free ferromagnetic layer having a magnetization that oscillates in the presence of an excitation current perpendicularly through the plane of the first free layer; a second free ferromagnetic layer having a magnetization that oscillates in the presence of an excitation current perpendicularly through the plane of the second free layer; and a nonmagnetic electrically conductive antiparallel coupling layer between said first and second free layers, the first and second free layers having substantially antiparallel magnetization directions in the absence of an excitation current; wherein at least one of the free layers is a damped free layer having a damping parameter greater than 0.05; and electrical circuitry connected to the set of layers for supplying an excitation current through the antiparallel coupling layer, the excitation current being selected from a direct current (DC) and an alternating current (AC) and having a current density greater than 10 7 A/cm 2 .