Ultrafast all-optical manipulation of magnetization in ferromagnetic thin films

Abstract

We report ultrafast all-optical manipulation of magnetization in ferromagnetic Co/Pt thin films, which are covered by an Au capping layer or Au nanoparticles. In the first configuration, we observe robust all-optical helicity-dependent switching of magnetization under different conditions. In the second configuration, the strong plasmonic resonance of Au nanoparticles results in an 18.5% decrease in the minimum laser power required to manipulate the magnetization.