Direct-Current Electrical Detection of Surface-Acoustic-Wave-Driven Ferromagnetic Resonance.

Surface acoustic wave (SAW) provides a promising platform to study spin-phonon coupling, which can be achieved by SAW-driven ferromagnetic resonance (FMR) for efficiently acoustic manipulation of spin. Although the magneto-elastic effective field model has achieved great success in describing SAW-driven FMR, the magnitude of the effective field acting on the magnetization induced by SAW still remain hard to access. Here, by integrating ferromagnetic stripes with SAW devices, we report direct-current detection for SAW-driven FMR based on electrical rectification. By analyzing FMR rectified voltage, we straightforwardly characterize and extract the effective fields, which exhibits advantages of better integration compatibility and lower cost than traditional methods such as vector network analyzer based techniques. Large nonreciprocal rectified voltage is obtained, which is attributed to the coexistence of in-plane and out-of-plane effective fields. The effective fields can be modulated by controlling the longitudinal and shear strains within the films to achieve almost 100% nonreciprocity ratio, demonstrating the potential for electrical switches. Besides the fundamental significance, our finding provides a unique opportunity for designable spin acousto-electronic device and its convenient signal readout. This article is protected by copyright. All rights reserved.