Magnetoelectricity in two-dimensional materials

TL;DR

This paper reviews the current state of research on two-dimensional magnetoelectric materials, highlighting theoretical expectations and experimental progress in fabricating low-dimensional versions with unique electromagnetic properties for potential applications.

Contribution

It provides a comprehensive overview of the theoretical and experimental advances in two-dimensional magnetoelectric materials, including novel methods like the extension of electrostatic image-charge techniques.

Findings

Magnetoelectric effects can be induced in 2D materials with potential for applications.

Theoretical models predict unique electromagnetic responses in 2D magnetoelectrics.

Experimental progress demonstrates feasibility of fabricating such low-dimensional materials.

Abstract

Since the initial isolation of few-layer graphene, a plethora of two-dimensional atomic crystals has become available, covering almost all known materials types including metals, semiconductors, superconductors, ferro- and antiferromagnets. These advances have augmented the already existing variety of two-dimensional materials that are routinely realized by quantum confinement in bulk-semiconductor heterostructures. This review focuses on the type of material for which two-dimensional realizations are still being actively sought: magnetoelectrics. We present an overview of current theoretical expectation and experimental progress towards fabricating low-dimensional versions of such materials that can be magnetized by electric charges and polarized electrically by an applied magnetic field - unusual electromagnetic properties that could be the basis for various useful applications. The interplay between spatial confinement and magnetoelectricity is illustrated using the paradigmatic example of magnetic-monopole fields generated by electric charges in or near magnetoelectric media. For the purpose of this discussion, the image-charge method familiar from electrostatics is extended to solve the boundary-value problem for a magnetoelectric medium in the finite-width slab geometry using image dyons, i.e., point objects having both electric and magnetic charges. We discuss salient features of the magnetoelectrically induced fields arising in the thin-width limit.