Abstract

The Dzyaloshinskii-Moriya (DM) interaction breaks chiral symmetry in magnets and it is instrumental in the stabilisation of skyrmions. In addition, the chiral DM interaction has a profound effect on the magnetization dynamics.

A skyrmion breathing mode (i.e., oscillations of the skyrmion radius) in chiral magnets is due to the breaking of the conservation of the total magnetization by the DM interaction. We describe nonlinear breathing oscillations in an antiferromagnet (AFM). We show that an expansion of the skyrmion can lead to its collapse and subsequent annihilation by internal (breathing) dynamics. The process can be efficient even when the skyrmion is only mildly excited.

Solitary wave behavior is exhibited by skyrmions in antiferromagnets, in contrast to the situation in ferromagnets. The particle-like character of AFM skyrmions is shown via their dispersion relation. The relativistic limit is linked to the spiral phase transition, manifesting the critical effect of the DM interaction in the dynamics.