Title: Integrated spin wave AND gate using iron garnet film

Spin wave (SW) attracts many interest as a candidate of post-CMOS device. Previously we demonstrated XNOR or AND/OR logic gates using interference of forward volume (FV) SW propagating in a 10 μm thick yttrium iron garnet (YIG) film [1]. However the size of these gate is mm order because YIG and electrodes for excitation and detection of SW were fabricated discretely. Therefore, integration of electrodes on YIG and miniaturization of YIG waveguide is essential for demonstration of further functionality.

In this work, we fabricated ψ-shape spin wave waveguide to demonstrate electrodes integrated AND logic gate. A 200 nm thick YIG was fabricated on garnet substrate using liquid phase epitaxy. YIG film was etched into ψ-shape using electron beam lithography and wet etching. The width of YIG film was 14 μm. Then four coplanar waveguides (CPWs) for excitation and detection of FV SW were placed on YIG waveguide. To measure a field dependence of propagation properties of FV SW, CPWs and vector network analyzer were connected via micro-prove to measure the scattering parameters. Successfully, the AND gate using FV SW phase interference was demonstrated, comparable to the case using 10 μm thick YIG. This is the smallest AND gate using spin wave.
[1] Sci. Rep. 7, 7898 (2017).