Ultrafast perturbation of magnetic domains by optical pumping in a ferromagnetic multilayer

Abstract

Ultrafast control of magnetism holds great promise for novel and efficient high-speed microelectronic devices. This includes manipulation of the domain walls that separate magnetic domains. Surprisingly, by use of a free-electron x-ray laser, the authors discover here that femtosecond laser pumping of a multidomain sample causes the domain walls to broaden from 29 to 51 nm in less than 1.6 picoseconds. They also find intriguing evidence of a simultaneous spatial rearrangement of domains. These unexpected results open new avenues for ultrafast optical manipulation of magnetism.