Soliton penetration from edges in a monoaxial chiral magnet

The magnetic solitons such as chiral solitons, magnetic skyrmions, and magnetic hopfions, exhibiting particlelike nature widely emerge in magnets depending on spatial dimension. As their number directly gives rise to an impact on magnetic properties and electronic properties, it is of great importance to control the number of solitons. However, a systematic study on dynamical processes to control the number of solitons, particularly by adding the desired number of solitons to the ground state exhibiting periodic arrangements of solitons, has been limited thus far. Here, we theoretically perform the systematic analysis for the dynamical control of the number of chiral solitons in monoaxial chiral magnets by effectively utilizing the edge modes whose excitation is localized near the edges. By studying the dynamical process associated with this edge mode in an applied rotating magnetic field by using the Landau-Lifshitz-Gilbert equation, we show that multiple soliton penetrations can take place until the system reaches the nonequilibrium steady state, and the number of infiltrated solitons successively increases with the amplitude of the rotating magnetic field after surpassing the threshold. We also clarify that the threshold amplitude of the rotating magnetic field can be reduced through the static magnetic field. Our results reveal that the desired number of solitons can be added within a certain range by taking advantage of the edge modes that appear without any special processing at the edges of the system. These results contribute to the development of an experimental way to control the number of solitons and are expected to be further applied to a wide range of magnetic solitons, not limited to chiral solitons.