Ultra-low energy threshold engineering for all-optical switching of magnetization in dielectric-coated Co/Gd based synthetic-ferrimagnet

Abstract

A femtosecond laser pulse is able to switch the magnetic state of a 3d-4f ferrimagnetic material on a pico-second time scale. Devices based on this all-optical switching (AOS) mechanism are competitive candidates for ultrafast memory applications. However, a large portion of the light energy is lost by reflection from the metal thin film as well as transmission to the substrate. In this paper, we explore the use of dielectric coatings to increase the light absorption by the magnetic metal layer based on the principle of constructive interference. We experimentally show that the switching energy oscillates with the dielectric layer thickness following the light interference profile as obtained from theoretical calculations. Furthermore, the switching threshold fluence can be reduced by at least $80\%$ to 0.6 mJ/cm${}^2$ using two dielectric SiO${}_2$ layers sandwiching the metal stack, which scales to 15 fJ of incident energy for a cell size of $50^2$ nm${}^2$.

References in corpus (9)

• Roadmap of spin-orbit torques
• Ultrafast Magnetization Reversal by Picosecond Electrical Pulses
• SOT-MRAM 300mm integration for low power and ultrafast embedded memories
• Multilayer optical calculations
• Integrating all-optical switching with spintronics
• Picosecond all-optical switching of magnetic tunnel junctions
• Comparing all-optical switching in synthetic-ferrimagnetic multilayers and alloys
• The role of electron and phonon temperatures in the helicity-independent all-optical switching of GdFeCo
• Enhanced all-optical switching and domain wall velocity in annealed synthetic-ferrimagnetic multilayers

Cited by in corpus (6)

• Picosecond Switching of Optomagnetic Tunnel Junctions
• Design of an integrated hybrid plasmonic-photonic device for all-optical switching and reading of spintronic memory
• Energy-efficient picosecond spin-orbit torque magnetization switching in ferro- and ferrimagnetic films
• Enhancing All-Optical Switching of Magnetization by He Ion Irradiation
• Magnetostatics of Room Temperature Compensated Co/Gd/Co/Gd-based Synthetic Ferrimagnets
• Integrated magneto-photonic non-volatile multi-bit memory