Magnetic response of a highly nonlinear soliton lattice in a monoaxial chiral helimagnet

Abstract

We present the theory of nonlinear ac magnetic response for the highly nonlinear regime of the chiral soliton lattice. Increasing of the dc magnetic field perpendicularly to the chiral axis results in crossover inside the phase, when nearly isolated $2\pi$-kinks are partitioned by vast ferromagnetic domains. Assuming that each of the kink reacts independently from the other ones to the external ac field, we demonstrate that internal deformations of such a kink give rise to the nonlinear response.