Telecommunications beyond 6G: first standalone spin-wave chip

A team of researchers at the Politecnico di Milano has developed the first silicon integrated microchip that uses spin waves. The study, published on Advanced Materials, is a decisive step towards the use of spin waves in the telecommunications of the future, far beyond current 5G and 6G standards.

The technology is based on magnonics, an emerging field that uses spin waves as an alternative to electrical signals. The spread of this technology has been restricted until now by the need for an external magnetic field, which has prevented it being incorporated into chips. The new device overcomes this hurdle, thanks to an innovative combination of permanent SmCo micromagnets and magnetic flux concentrators, it can operate completely autonomously. 

The chip is miniaturised (100 × 150 square micrometres, so much smaller than current radiofrequency signal processing devices based on acoustic waves) and compatible with existing electronic platforms.  The transverse magnetic field can be modulated very precisely by varying the distance between the magnets and concentrators to between 11 and 20.5 mT. This enables the operating frequency to be adjusted to between 3 and 8 GHz, and the phase shift to be tuned up to 120 degrees at 6 GHz in this first prototype.

As well as demonstrating the principle of the technology, the researchers point out that the prototypes are already functioning as time delay lines and phase shifters, without the application of an external bias field.