Demonstration of a robust magnonic spin wave interferometer

Area of Science:

• Physics
• Materials Science
• Electrical Engineering

Background:

• Magnonics offers ultralow power logic circuits using spin waves for information processing.
• Spin wave interference enables multi-input logic gates, but stability issues have hindered development.
• Isotropic spin waves, like forward volume waves, are ideal but prone to reflection.

Purpose of the Study:

• To develop a robust spin wave interferometer.
• To enable the use of spatially isotropic spin waves in magnonic devices.
• To overcome limitations posed by spin wave reflection at waveguide edges.

Main Methods:

• Fabrication of a spin wave absorber using a yttrium iron garnet waveguide partially covered by gold.
• Experimental demonstration of the spin wave absorber's functionality as an interferometer.
• Characterization of the device's performance, including ON/OFF isolation.

Main Results:

• The developed spin wave absorber effectively stabilizes interfering isotropic spin waves (forward volume mode).
• The device functions as a robust spin wave interferometer.
• A high ON/OFF isolation value of 13.7 dB was achieved, even in magnetic fields exceeding 30 Oe.

Conclusions:

• The gold-covered yttrium iron garnet waveguide acts as an effective spin wave absorber, enabling stable magnonic interferometers.
• This advancement facilitates the realization of multi-input logic gates using isotropic spin waves.
• The findings contribute to the development of energy-efficient magnonic logic circuits.