Magnetic Proximity Effect and Interlayer Exchange Coupling of Ferromagnetic/Topological Insulator/Ferromagnetic Trilayer

TL;DR

This paper theoretically explores the interlayer exchange coupling in ferromagnetic/Topological Insulator/ferromagnetic trilayers, revealing how electronic states influence magnetic interactions and offering insights for ultrafast magnetic storage device design.

Contribution

It provides a theoretical analysis of interlayer exchange coupling in FMI/TI/FMI structures, identifying electronic state contributions and tunability of magnetic interactions.

Findings

Electronic states of TI influence coupling behavior.

Coupling constant can be tuned via electronic states.

Structure serves as a platform for magnetic interface analysis.

Abstract

Magnetic proximity effect between topological insulator (TI) and ferromagnetic insulator (FMI) is considered to have great potential in spintronics. However, a complete determination of interfacial magnetic structure has been highly challenging. We theoretically investigate the interlayer exchange coupling of two FMIs separated by a TI thin film, and show that the particular electronic states of the TI contributing to the proximity effect can be directly identified through the coupling behavior between two FMIs, together with a tunability of coupling constant. Such FMI/TI/FMI structure not only serves as a platform to clarify the magnetic structure of FMI/TI interface, but also provides insights into designing the magnetic storage devices with ultrafast response.