One-Dimensional Magnonic Crystal With Cu Stripes for Forward Volume Spin Waves

Abstract

A one-dimensional magnonic crystal for forward volume spin waves (FV SWs) is demonstrated using eight pairs of Cu stripes fabricated on a 1-mm wide × 14-mm long × 10.2-µm thick yttrium iron garnet (YIG) waveguide and a SW absorber of 30-nm-thick Au film. The development of this crystal is challenging due to strong spectral oscillations caused by edge reflections and process difficulties associated with YIG magnonic crystals. A magnonic band gap with a depth of −4.6 dB is observed at a frequency of 1.80 GHz for a FV SW excited by a 50-µm-wide microstrip line, which is in good agreement with simulation results using three-dimensional modeling in the radio frequency region. The obtained performance is illustrated by plotting the depth of the respective band gaps vs the pair number of the stripes. This value is compared with that obtained in previous studies.