High frequency susceptibility of a weak ferromagnet with magnetostrictive magnetoelectric coupling: using heterostructures to tailor electromagnon frequencies

TL;DR

This paper investigates the high-frequency magnetoelectric susceptibility of weak ferromagnetic thin films with magnetostrictive coupling and explores heterostructures to generate electromagnon modes in the microwave range for potential applications.

Contribution

It introduces a theoretical framework for understanding dynamic coupling in ferroelectric and weak ferromagnetic thin films and proposes heterostructures to tailor electromagnon frequencies.

Findings

Dynamic coupling between ferroelectric and antiferromagnetic excitations identified.

Heterostructures can generate electromagnon modes in the microwave regime.

Dipolar magnetic fields facilitate coupling between different magnetic and electric modes.

Abstract

In the first part of this work we calculate the high frequency magnetoelectric susceptibility of a simultaneously ferroelectric and canted antiferromagnetic (also know as weak ferromagnetic) thin film with magnetostrictive magnetoelectric coupling. We show that a dynamic coupling exists between the ferroelectric and optic antiferromagnetic excitations. In the second part of the paper, we calculate using an effective medium method the susceptibility of a heterostructure comprising alternating thin films of such a material together with a ferromagnet. Dipolar magnetic fields serve to couple the ferromagnetic and optic antiferromagnetic modes, which in turn couples the ferromagnetic and ferroelectric excitations. This provides a mechanism for creating "electromagnon" modes in the microwave regime which may be useful for applications.