Plasmon-Enhanced Optical Control of Magnetism at the Nanoscale via the Inverse Faraday Effect

Abstract

The relationship between magnetization and light has been the subject of intensive research for the past century. Herein, the impact of magnetization on light polarization is well understood. Conversely, the manipulation of magnetism with polarized light is being investigated to achieve all-optical control of magnetism, driven by potential technological implementation in spintronics. Remarkable discoveries, such as the single-pulse all-optical switching of magnetization in thin films and submicrometer structures, have been reported. However, the demonstration of local optical control of magnetism at the nanoscale has remained elusive. Herein, it is demonstrated that exciting gold nanodiscs with circularly polarized femtosecond laser pulses lead to ultrafast, local, and deterministic control of magnetization in an adjacent magnetic film. This control is achieved by exploiting the magnetic moment generated in plasmonic nanodiscs through the inverse Faraday effect. The results pave the way for light-driven control in nanoscale spintronic devices and provide important insights into the generation of magnetic fields in plasmonic nanostructures.