Mutual Phase-Locking of Microwave Spin Torque Nano-Oscillators

The spin torque effect is a consequence of the continued, required scaling of magnetic devices. The output of this device can be frequency modulated, phase-locked to a stable external source, and mutually phase-locked to a neighboring oscillating contact. Measurements further indicate that the oscillators are also phase-locked during the coincidence of their frequencies. We have verified that the combined output power during locking is proportional to the square of the sum of the individual oscillators' voltage outputs as expected for the combination of two coherent signals. Furthermore this data implies a possibility to significantly increase oscillator power output from a micro-scale device by utilizing an array of N phase-locked oscillators with combined output power proportional to N
²
.