[18a-D704-1~11] 10.2 Fundamental and exploratory device technologies for spin

▲ [18a-D704-2] Phonon-magnon coupling in a synthetic antiferromagnet integrated into a surface acoustic wave cavity

〇Hiroki Matsumoto¹, Daiki Hatanaka², Motoki Asano², Takuya Kawada¹, Masashi Kawaguchi¹, Masamitsu Hayashi¹ (1.The Univ. of Tokyo, 2.NTT-BRL)

Keywords:synthetic antiferromagnet, phonon-magnon coupling, surface acoustic wave

Cavity magnomechanics, as an analogy of cavity optomechanics and cavity optomagnonics, offers a powerful platform to study coherent phonon-magnon interaction. Recently, phonon-magnon coupling in a ferromagnetic thin film integrated into a surface acoustic wave (SAW) resonator was experimentally demonstrated. This “on-chip SAW cavity” is a promising technology for future quantum circuit implementation of phonon-magnon interaction. For efficient quantum information processing, the phonon-magnon coupling constant needs to be enhanced by engineering not only ferromagnetic materials but also the film structures. In this work, we investigate phonon-magnon coupling in a tri-layer synthetic antiferromagnet (SAF) composed of a non-magnetic layer sandwiched by two ferromagnetic layers using a SAW cavity. The ferromagnetic layers antiferromagnetically couple because of an interlayer exchange interaction. We use a tri-layer CoFeB/Ru/CoFeB SAF, where SAW-spin wave conversion was recently reported.