[10a-S302-1~11] 10.2 Fundamental and exploratory device technologies for spin

▲ [10a-S302-4] Large nonreciprocity of surface acoustic waves in a synthetic antiferromagnet

〇Hiroki Matsumoto¹, Takuya Kawada¹, Masashi Kawaguchi¹, Masamitsu Hayashi¹ (1.The Univ. of Tokyo)

Keywords:nonreciprocity, surface acoustic wave, synthetic antiferromagnet

Nonreciprocity of surface acoustic waves (SAW) in a ferromagnetic (FM) thin film is gaining much attention in recent years. In addition to the nonreciprocity originating from helicity mismatch between SAW and spin waves, highly nonreciprocal spin wave dispersion in a dipole-coupled FM bilayer with nonmagnetic spacer (~5 nm) makes it possible to realize a large amplitude nonreciprocity of SAW with a value larger than 90%. In the system, dipole-interaction between stray fields and the dynamic magnetization induces the nonreciprocity of spin wave, causing the nonreciprocity of SAW via magnetoelastic and magneto-rotation coupling. The nonreciprocity of SAW in a synthetic antiferromagnet, however, is yet to be reported experimentally, although a large nonreciprocity of SAW in a wide frequency range is predicted theoretically. We report a large nonreciprocity of SAW in a synthetic antiferromagnet in the presentation.