Abstract
All-optical spin switching (AOS) represents a new frontier in magnetic storage technology—spin manipulation without a magnetic field—but its underlying working principle is not well understood. Many AOS ferrimagnets such as GdFeCo are amorphous and renders the high-level first-principles study unfeasible. The crystalline half-metallic Heusler presents an opportunity. Here we carry out hitherto the comprehensive density functional investigation into the material properties of , and introduce two concepts—the spin anchor site and the optical active site—as two pillars for AOS in ferrimagnets. In serves as the spin anchor site, whose band is below the Fermi level and has a strong spin moment, while is the optical active site whose band crosses the Fermi level. Our magneto-optical Kerr spectrum and band structure calculation jointly reveal that the delicate competition between the Ru- and Ga- states is responsible for the creation of these two sites. These two sites found here not only present a unified picture for both and GdFeCo, but also open the door for future applications. Specifically, we propose a magnetic tunnel junction where a single laser pulse can control magnetoresistance.
- Received 14 December 2021
- Revised 9 February 2022
- Accepted 17 February 2022
DOI:https://doi.org/10.1103/PhysRevB.105.054431
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