Magnon-plasmon coupling mediated by linear magnetoelectric effect in two-dimensional crystals with Dzyaloshinskii-Moriya interaction

TL;DR

This paper introduces a new mechanism for magnon-plasmon hybridization in two-dimensional materials, driven by linear magnetoelectric effects, and demonstrates how external electric fields can tune this coupling.

Contribution

It proposes a novel magnon-plasmon coupling mechanism based on linear magnetoelectric interaction in 2D crystals with Dzyaloshinskii-Moriya interaction, and explores electric field tuning.

Findings

Derived magnon-plasmon coupling parameter proportional to magnetoelectric constant

Calculated dispersion relations for hybridized modes

Showed electric field tuning of magnon modes and coupling

Abstract

Recently, one can observe a renewed interest in coupling of spin waves (magnons) and collective charge oscillations (plasmons), especially in two-dimensional systems. Several mechanisms of the magnon-plasmon hybridization in ferromagnetic and antiferromagnetic systems have been proposed. Here, we consider another mechanism of magnon-plasmon hybridization, which is based on the linear magnetoelectric interaction. As a specific system we consider a monolayer of vanadium-based diselenide with perpendicular easy-axis magnetic anisotropy and Dzialoshinskii-Moriya interaction. The derived parameter of magnon-plasmon coupling is proportional to the magnetoelectric constant. Assuming for this constant an adequate experimental value, we calculate dispersion relations of the hybridized magnon-plasmon mods. Moreover, we also show that an external electric field normal to the layer (due to a gate voltage) can be used as a tool to tune the magnon modes and this way also hybridized magnon-plasmon coupling. A specific case of magnon-plasmon coupling based on tuning Dzialoshinskii-Moriya interaction is also considered.