Bound-state spin-wave spectroscopy exploiting nonlinear three-magnon processes

One recent breakthrough in the field of magnonics is the experimental realization of reconfigurable spin-wave nanochannels formed by a magnetic domain wall with a width of 10–100 nm. This remarkable progress enables an energy-efficient spin-wave propagation with a well-defined wave vector along its propagating path inside the wall. In the mentioned experiment, a microfocus Brillouin light scattering spectroscopy was taken in a line-scans manner to measure the frequency of the bounded spin wave. Due to their localization nature, the confined spin waves can hardly be detected from outside the wall channel, which guarantees the information security to some extent. In this work, we theoretically propose a scheme to detect/eavesdrop on the spin waves inside the domain-wall nanochannel via nonlinear three-magnon processes [1]. The approach can be parallelly applied for probing the Dzyaloshinskii-Moriya interaction in narrow magnetic stripes [2]. The idea is analytically formulated with micromagnetic simulations performed to verify the theoretical predictions.
[1] Beining Zhang, Zhenyu Wang, Yunshan Cao, Peng Yan, and X.R. Wang, Phys. Rev. B 97, 094421 (2018).
[2] Zhenyu Wang, Beining Zhang, Yunshan Cao, and Peng Yan, Phys. Rev. Applied (2018) (in press).