Four-Port Characterization of YIG Magnonic Device: A Way to Improve Magnetic Sensors Based on YIG Device

For several years, considerable attention has been devoted to advancing high-sensitivity magnetic sensors to enhance measurement capabilities. A recent trend in this pursuit involves leveraging magnonic devices for sensor implementation. While only a limited number of studies have produced and characterized such devices, initial performance outcomes appear promising. These devices harness the spin wave propagation dependency on external magnetic fields. Typically, yttrium iron garnet (YIG) serves as the magnetic material. The implementation of the sensor system involves several elements. A permanent magnetic field must saturate the material. An ac current passing through an exciting antenna generates spin waves by locally causing a precession of the magnetic moment. A receiving antenna is used to capture the propagated spin wave. A representation of the observed external magnetic field is obtained by demodulating the received signal. Optimizing this system necessitates the development of a comprehensive model. However, existing physical models primarily focus on spin wave propagation and generation. Our proposed approach adopts a holistic, systemic perspective, treating the sensor element as a four-port coupler. This model underscores the intrinsic symmetries of the sensing element and the non-reciprocal nature of spin wave propagation. Notably, our work presents a unified model that accounts for spin wave propagation within microstructured YIG, as well as spin wave reflections along YIG edges, facilitating the assessment of each parameter’s impact on the overall system response. This work presents our latest advancements in the field. Several systems and configurations have been tested, enabling the characterization of various parameters of the couplers. These results were used to explore new ways to optimize the magnonic sensor.