Spin Dynamics in van der Waals Magnetic Systems

TL;DR

This review summarizes recent progress in studying spin dynamics of 2D van der Waals magnetic materials using various ferromagnetic resonance techniques, highlighting their importance for ultrafast spintronic applications.

Contribution

It provides a comprehensive overview of FMR methods applied to 2D vdW magnets and discusses recent advances and future research opportunities in this rapidly evolving field.

Findings

Broadband FMR, optical FMR, and spin-torque FMR are key techniques for probing 2D vdW magnet spin dynamics.

Recent advances include laboratory- and synchrotron-based FMR techniques.

Understanding spin dynamics aids in designing ultrafast spintronic devices.

Abstract

The discovery of atomic monolayer magnetic materials has stimulated intense research activities in the two-dimensional (2D) van der Waals (vdW) materials community. The field is growing rapidly and there has been a large class of 2D vdW magnetic compounds with unique properties, which provides an ideal platform to study magnetism in the atomically thin limit. In parallel, based on tunneling magnetoresistance and magneto-optical effect in 2D vdW magnets and their heterostructures, emerging concepts of spintronic and optoelectronic applications such as spin tunnel field-effect transistors and spin-filtering devices are explored. While the magnetic ground state has been extensively investigated, reliable characterization and control of spin dynamics play a crucial role in designing ultrafast spintronic devices. Ferromagnetic resonance (FMR) allows direct measurements of magnetic excitations, which provides insight into the key parameters of magnetic properties such as exchange interaction, magnetic anisotropy, gyromagnetic ratio, spin-orbit coupling, damping rate, and domain structure. In this review article, we present an overview of the essential progress in probing spin dynamics of 2D vdW magnets using FMR techniques. Given the dynamic nature of this field, we focus mainly on broadband FMR, optical FMR, and spin-torque FMR, and their applications in studying prototypical 2D vdW magnets. We conclude with the recent advances in laboratory- and synchrotron-based FMR techniques and their opportunities to broaden the horizon of research pathways into atomically thin magnets.