A leading nonlinear effect in magnonics is the interaction that splits a high-frequency magnon into two low-frequency ones with conserved linear momentum. Here, we report experimental observation of nonlocal three-magnon scattering between spatially separated magnetic systems, viz. a CoFeB nanowire and an yttrium iron garnet (YIG) thin film. Above a certain threshold power of an applied microwave field, a CoFeB Kittel magnon splits into a pair of counter-propagating YIG magnons that induce voltage signals in Pt electrodes on each side, in excellent agreement with model calculations based on the interlayer dipolar interaction. The excited YIG magnon pairs reside mainly in the first excited (n=1) perpdendicular standing spin-wave mode. With increasing power, the n=1 magnons successively scatter into nodeless (n=0) magnons through a four-magnon process. Our results help to assess non-local scattering processes in magnonic circuits that may enable quantum entanglement between distant magnons for quantum information applications.
@article{arxiv.2209.01875,
title = {Nonlocal detection of interlayer three-magnon coupling},
author = {Lutong Sheng and Mehrdad Elyasi and Jilei Chen and Wenqing He and Yizhan Wang and Hanchen Wang and Hongmei Feng and Yu Zhang and Israa Medlej and Song Liu and Wanjun Jiang and Xiufeng Han and Dapeng Yu and Jean-Philippe Ansermet and Gerrit E. W. Bauer and Haiming Yu},
journal= {arXiv preprint arXiv:2209.01875},
year = {2023}
}