Power absorption in acoustically driven ferromagnetic resonance

Surface acoustic waves (SAWs) have recently been used to drive ferromagnetic resonance by exploiting the coupling between strain and magnetization in magnetostrictive materials in a technique called acoustically driven ferromagnetic resonance (ADFMR). In this work, we quantitatively examine the power absorbed by the magnetic elements in such systems. We find that power absorption scales exponentially with the length of the magnetic element in the direction of SAW propagation, with the rate of scaling set by the thickness of magnetic material. In addition, we find that ADFMR behaves consistently across a wide range of input power values (>65 dB). Our results indicate that devices such as filters, oscillators, and sensors can be designed that operate with very low power, yet provide high tunability.