Double-peaked resonance in harmonic-free acoustically driven ferromagnetic resonance

The resonant interaction between surface acoustic waves and ferromagnetic thin films, a phenomenon known as acoustically driven ferromagnetic resonance (ADFMR), provides a way to control magnetic resonance with purely voltage excitation. However, devices have historically been operated at harmonic frequencies, leading to large insertion losses. In this work, we demonstrate a harmonic-free drive of ADFMR devices where the strain reaches very high values, comparable to the saturation magnetostriction of the magnetic element. The acoustic energy transfer is highly efficient and reaches almost 99.9%. Furthermore, we report the presence of multiple absorption maxima across the range of applied magnetic fields, a property not previously observed in the literature.