Standalone Integrated Magnonic Devices

In the race toward "beyond 6G" telecommunication platforms, magnonics emerges as a promising solution. To date, however, the requirement for bulky external sources of the magnetic bias field necessary for spin wave propagation has constituted a significant bottleneck, impeding the integration of magnonic devices into RF systems. Here, the first demonstration is presented of a standalone and tunable magnonic device featuring all-electric input and output, fully integrated on a silicon substrate, with a compact footprint of 100 × 150 µm². The device consists of a CoFeB waveguide equipped with two radio frequency antennas, flanked by a symmetric configuration of magnetic flux concentrators and SmCo permanent micromagnets. By varying the distance D between the flux concentrators and the permanent magnets from 0 to 12 µm, the transverse bias field can be tuned from 20.5 to 11 mT, respectively. This variation directly modulates the dispersion relation of Damon-Eshbach spin wave modes in the CoFeB waveguide. In the proof-of-concept devices, the spin wave frequency band ranges from 3 to 8 GHz, with precise tuning of the phase shift up to 120 deg at 6 GHz. The operational frequency band can be easily pushed to higher frequencies through micromagnet engineering.