Spontaneous domain nucleation under in-plane fields in ultrathin films with Dzyaloshinskii-Moriya interaction

Abstract

In this paper, we show that applying a hard axis field reduces the energy barrier for the spontaneous formation of a multi-domain state in magnetic ultrathin films sandwiched between a heavy metal and an oxide. This provides a simple technique to generate a metastable multi-domain state in magnetic films where the ground state is uniform. This approach could be particularly interesting in materials with strong Dzyaloshinskii-Moriya interaction as a means to realize metastable chiral textures.

Initialization‐Free Multilevel States Driven by Spin–Orbit Torque Switching

“…That is, as long as the multidomain configuration exists, the multilevels can still be achieved. The SOT switching mechanism due to multidomain formation can be well controlled by the energy competition between magnetostatic energy and domain wall energy—for example, by adjusting the thickness of the ferromagnet (manipulating the magnetostatic energy) or by engineering the Dzyaloshinskii–Moriya interaction at the interfaces (changing the domain wall energy) . For a rough estimate, consider the situation when the cell size is scaled down to 50 nm × 50 nm.…”