부산대학교 도서관

The gyromagnetic effect, i.e. one of the most significant discoveries in physics, is associated with a mutual conversion of angular momentum between macroscopic mechanical rotation and microscopic electron spin. The gyromagnetic field produced by a feasible mechanical rotor is, however, too small for practical applications. Surface acoustic wave is a promising candidate to improve the gyromagnetic effect because an elliptical oscillation of lattice with a frequency of GHz order can be realized. Here, experimental demonstrations on a gyromagnetic spinwave excitation and its reciprocal effect, i.e. a phase shift of the acoustic wave, are presented. Furthermore, we also show that the gradient of the acoustic gyromagnetic field can produce an alternating spin current, whose amplitude is increased nonlinearly with the frequency.