Characteristics of parametric spin waves in rectangular magnonic blocks

Abstract

Abstract The characteristics of parametric spin-wave pumping are investigated in three rectangular permalloy blocks with in-plane aspect ratios of 12, 6, and 4. Micro-Brillouin light scattering (BLS) spectroscopy is utilized to detect the intrinsic properties of excited spin waves under various excitation conditions of an external magnetic field and microwave power. Based on the theoretical dispersion relation and BLS intensity and its spatial profile, the parametric spin wave with a frequency of f sw = 5 .6 GHz is found to be excited in fundamental mode in a block of largest aspect ratio while the other block have higher-order or edge-localized modes along the width direction. The data shows that the nature of spin waves is quite sensitive on the conditions of sample geometry, applied field and microwave power. Thus, with the appropriate combination of the three parameters, it would be possible to control the nature of spin wave in each block simultaneously, which increase the blocks’ potential in magnonic applications, such as spin-logic and interferometer.