We performed time domain propagating spin-wave (SW) spectroscopy to investigate SW soliton formation. By choosing backward volume SW mode, we successfully observed a multiple solitons formation and propagation. The SW power dependence on the duration of excitation signal showed nonlinear dependence, and SW maintained its wave packet width. By making a contour plot of SW power, the evolution of SW soliton was clearly demonstrated. The generation and annihilation of SW soliton exhibited a complicated behavior, showing the competition between nonlinear effect and dispersion/relaxation effects.

A new class of information technology, called magnonics, has been employed to develop several information-processing functionalities, such as logic gates, majority gates, and multiplexers. However, the application of these functionalities has been limited because the transmission loss of spin-wave signals makes combining these functionalities challenging. A promising technique called spin-wave soliton train was developed by experimental pioneers, however, the problem of information density was not yet overcome. In this study, a generation method of soliton train was revisited, and a 10 times larger density of spin-wave soliton train was achieved in time-domain electric experiments.