Spin-wave cochlea and nonlocal magnetic resonance in a magnet

Spatial dependence of magnetization dynamics in a Y3Fe5O12 film exposed to a magnetic-field gradient has been investigated by measuring local spin pumping and inverse spin-Hall effects. The result shows that, when microwaves are irradiated locally, magnetization precession is excited at a far distant position from the microwave irradiation position. By measuring the field and microwave frequency dependence, we found that the observed magnetization dynamics is attributed to nonlocal resonance of magnetization as well as the spatial change in the spin-wave dispersion under the magnetic-field gradient, which can be applied to realizing an innate microwave spectrometer: a spin-wave cochlea.

Automated summary

The spatial dependence of magnetization dynamics in a Y3Fe5O12 film under a magnetic-field gradient is investigated using local spin pumping and inverse spin-Hall effects. The results show that when microwaves are irradiated locally, magnetization precession is excited at a distant position from the irradiation location. By analyzing the field and microwave frequency dependence, it is found that the observed magnetization dynamics are due to nonlocal resonance of magnetization and spatial changes in spin-wave dispersion under the magnetic-field gradient, suggesting the potential to realize a microwave spectrometer known as a spin-wave cochlea.