Equilibrium magnetization at the boundary of a magnetoelectric antiferromagnet

TL;DR

This paper demonstrates that boundaries of magnetoelectric antiferromagnets inherently possess an equilibrium magnetization that can be manipulated with electric and magnetic fields, enabling potential applications in nanoelectronics.

Contribution

It introduces a symmetry-based framework showing boundary magnetization in magnetoelectric antiferromagnets and its controllability, highlighting its use as a non-volatile switchable state.

Findings

Boundary magnetization exists at the surface of magnetoelectric antiferromagnets.

Boundary magnetization can be switched with E and B fields.

Boundary magnetization can be significantly enhanced if symmetry is broken at the boundary.

Abstract

Symmetry arguments are used to show that a boundary of a magnetoelectric antiferromagnet has an equilibrium magnetization. This magnetization is coupled to the bulk antiferromagnetic order parameter and can be switched along with it by a combination of E and B fields. As a result, the antiferromagnetic domain state of a magnetoelectric can be used as a non-volatile switchable state variable in nanoelectronic device applications. Mechanisms affecting the boundary magnetization and its temperature dependence are classified. The boundary magnetization can be especially large if the boundary breaks the equivalence of the antiferromagnetic sublattices.