Investigation of deterministic and cumulative nature in helicity-dependent optical switching of ferrimagnetic Gd–Fe–Co films

The precise control of magnetization using circularly polarized laser pulses in perpendicularly magnetized films is a key approach to develop storage media. Although deterministic helicity-dependent magnetization switching (HDMS) in a single-pulse excitation has been observed in ferrimagnetic Gd–Fe–Co alloys, ferromagnetic [Co/Pt]_N multilayers require cumulative effects of multiple pulses to achieve HDMS. In this study, we systematically investigated the single-shot and cumulative nature of HDMS using ferrimagnetic Gd–Fe–Co films with varying compositions and multilayer structures, in terms of angular momentum compensation, thermal diffusion, mobility of domain walls, and the size of the magneto-optical effect. These results provide insights for the realization of single-shot HDMS in various magnetic systems, such as ferromagnetic alloys.