Field-Free Electrical Switching of Perpendicular Magnetization via Domain-Wall-Free Textures in Ferrimagnets

Discovering and effectively leveraging nontrivial magnetic texture in magnetic materials is of great significance for developing next-generation spintronic devices. In this Letter, we demonstrate that solid-state hydrogen gating in rare-earth-transition-metal ferrimagnetic alloys can reversibly create and remove an unconventional magnetic texture called magnetic domains without domain walls, i.e., two adjacent magnetic regions have opposite net magnetization but rare-earth sublattices in these two regions have the same magnetic moment direction. By introducing this nontrivial magnetic texture, spin-orbit torque driven perpendicular magnetization switching is realized in the absence of an external magnetic field. The continuous magnetization reduction tendency of two magnetic sublattices at the boundary between two magnetic domains is responsible for the observed field-free switching phenomenon. Our Letter provides an alternative to leverage spin texture characteristics in information writing and promotes the application of ferrimagnets in spintronic devices.