Improvement of the magnon-magnon coupling strength in Y3Fe5O12/ Py heterostructures

Magnon-quasiparticle couplings perform magnon information transferences and transports, thus controlling the coupling strengths is significant for novel information function devices. Here, we report the modulation of the magnon-magnon (M-M) coupling strength in Y3Fe5O12/permalloy (YIG/Py) heterostructures via ferromagnetic resonance (FMR) technique. The anti-crossing gap gc enhances 80 Hz by changing the radio frequency (rf) mi-crowave power, which could be ascribed to the enhancement of the dipolar interaction and spin pumping effect. Furthermore, the gc decreases with the increasing angle theta between external magnetic field and rf current due to the increase of magnon relaxation. Moreover, the FMR linewidths change with increasing angle theta due to the magnetic anisotropy parameters and the two-magnon relaxation mechanism induced by the more oblique external field.