A new paper from the RadioSpin consortium, published in Nature Communications, reports the mutual synchronization of spin-torque nano-oscillators (STNOs) through a carefully engineered dipolar coupling mechanism.
Synchronizing multiple oscillators is one of the central challenges on the road to practical spintronic RF systems. Individually, STNOs emit low power and relatively broad spectral lines; locked together, an array behaves as a single coherent source with far better signal quality. The work describes how the geometry and spacing of neighbouring oscillators can be tuned so that their magnetic fields lock them into a common phase without the need for external wiring.
The measurements show a clear narrowing of the emission linewidth and an increase in output power as additional oscillators join the synchronized state, in close agreement with the theoretical model developed within the consortium.
The result is an important building block for the communication and computing demonstrators being assembled in the later phase of the project, and points toward scalable arrays of coupled nanoscale oscillators.