Electrical control of magnons in multiferroic NiI$_2$

TL;DR

This study demonstrates how an external electric field can control magnonic properties in monolayer NiI$_2$, a 2D multiferroic, enabling electrical tuning of spin-wave transport for advanced spintronic applications.

Contribution

It reveals the electric control of magnon spectra in 2D NiI$_2$ via ab initio calculations, highlighting the magnetoelectric coupling's role in tunable magnonic devices.

Findings

Electric field induces magnon spectrum splitting.

Ferroelectric polarization affects magnon energy levels.

Magnetoelectric coupling enables tunable magnon properties.

Abstract

Layered van der Waals two-dimensional (2D) magnets are a cornerstone of ultrathin spintronic and magnonic devices. The recent discovery of a 2D multiferroic with strong magnetoelectric coupling in NiI$_2$ offers a promising platform for the electrical control of spin-wave transport. In this work, using ab initio calculations, we investigate how the magnonic properties of monolayer NiI$_2$ can be controlled using an external electric field. We show that the emergence of a ferroelectric polarization leads to an energy splitting in the magnon spectrum, thus establishing a way to detect the electric polarization experimentally. We also show the modulation of the magnon splitting and the energy position of the singularities in magnon DOS by an electric field due to the strong magnetoelectric coupling. Our results highlight the interplay between ferroelectricity and magnons in van der Waals multiferroics and pave the way to design electrically tunable magnetic devices at the 2D limit.