Identification and minimization of losses in microscale spin-wave transducers

Magnonics is a promising platform for integrated radio-frequency (rf) devices, leveraging its inherent nonreciprocity and reconfigurability. However, the efficiency of spin-wave transducers driven by rf currents remains a major challenge. In this study, we systematically investigate a spin-wave transducer composed of micrometer-sized rf antennas on yttrium iron garnet films of different thickness—an ideal testbed for integrated magnonic devices. Using propagating spin-wave spectroscopy, we analyze spin-wave transmission, identifying key loss mechanisms and improving device efficiency by reducing ohmic resistance. The resulting improvements enable the reduction of insertion loss to below 10 dB in microscaled spin-wave transducers. At the same time large nonreciprocity can be exploited to achieve significant isolation on the microscale.