Gd Doping at the Co/Pt Interfaces to Induce Ultrafast All-Optical Switching

Single-pulse all-optical switching has mainly been observed and studied in transition-metal-Gd-based thin films with high potential for enabling new application for energy-efficient and fast magnetic data storage, memory, or logic. For GdCo alloys, ultrafast single-pulse switching has only been observed close to the compensation composition, in agreement with theoretical predictions. Here, we demonstrate that starting with a [Co/Pt] bilayer showing strong perpendicular anisotropy, a small Gd dusting at the interface is sufficient to induce a well-defined single-pulse all-optical switching. A careful analysis of the impact of the Gd–Co interface on all optical switching is presented. The opportunity to perform single-pulse all-optical switching with a very little amount of Gd opens perspectives for its applicability but also questions the theoretical understanding of the toggle switching underlying mechanism.