Hybrid magnonic–spintronic system for tunable broadband signal filtering and microwave generation

Non-conventional beyond-the-state-of-the-art signal processing schemes require parallelism, scalability, robustness, and energy efficiency to meet the demands of complex data-driven applications. With further research, magnonic and spintronic circuits can potentially help to fulfil these requirements. We report on an experimental realization of a hybrid device that can employ broad deteriorated microwave signals to excite and detect low energy propagating spin waves (SWs). For this, we use the output signal of a spin-transfer torque nano-oscillator (STNO) and connect it to a radio-frequency (RF) filter based on a magnonic delay-line. The STNO serves as a tunable nano-scaled signal generator with a broad output linewidth. Its RF output is fed as input into the magnonic delay-line circuit. Tuning the magnetic field solely at the magnonic circuit, we demonstrate the capability to selectively filter a broad RF input, obtaining a spin-wave output signal with a much narrower linewidth. This allows us to tune the frequency of the RF signal at the output simply by tuning the magnetic field. These results represent an initial demonstration toward a versatile, energy-efficient, and compact wave-based filter with high sensitivity. Such a device can use even low-power, degraded signals and convert them into tunable SW outputs, effectively reducing the need for charge-based signal processing.