• DOI:10.1063/5.0077491
• Corpus ID: 239768882

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

@article{Li2021UltralowET,
  title={Ultra-low energy threshold engineering for all-optical switching of magnetization in dielectric-coated Co/Gd based synthetic-ferrimagnet},
  author={Pingzhi Li and Mark J.G. Peeters and Youri L. W. van Hees and Reinoud Lavrijsen and Bert Koopmans},
  journal={Applied Physics Letters},
  year={2021}
}

• Pingzhi Li, Mark J.G. Peeters, +2 authors B. Koopmans
• Published 22 October 2021
• Physics
• Applied Physics Letters

A femtosecond laser pulse is able to switch the magnetic state of a 3d-4f ferrimagnetic material on a picosecond 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 using two dielectric SiO2 layers sandwiching the metal stack, which scales to 15 fJ of incident energy for a cell size of 50 nm.