Magnetic domain wall dynamics in the precessional regime: Influence of the Dzyaloshinskii-Moriya interaction

The domain wall dynamics driven by an out-of-plane magnetic field was measured for a series of magnetic trilayers with different strengths of the interfacial Dzyaloshinskii-Moriya interaction (DMI). The features of the field-driven domain wall velocity curves strongly depend on the ratio of the field H-D stabilizing chiral Neel walls to the demagnetizing field within the domain wall, H-DW. The measured Walker velocity, which in systems with large DMI is maintained after the Walker field, giving rise to a velocity plateau up to the Slonczewski field H-S, can be related to the DMI strength. Yet, when H-D and H-DW have comparable values, a careful analysis needs to be done in order to evaluate the impact of the DMI on the domain wall velocity. By means of a one-dimensional model and two-dimensional simulations, we extend this method and we clarify the interpretation of the experimental curves measured for samples where H-D and H-DW are comparable.