Design and theory of switchable linear magnetoelectricity by ferroelectricity in Type-I multiferroics

TL;DR

This paper provides a comprehensive theoretical framework for switchable linear magnetoelectric effects in Type-I multiferroics, identifying two distinct pathways for nonvolatile coupling based on spin-space symmetry and proposing stable compounds for experimental validation.

Contribution

It introduces a universal scheme for realizing nonvolatile magnetoelectric coupling in Type-I multiferroics, highlighting two mutually exclusive mechanisms and offering design principles for robust control.

Findings

Two pathways for ME coupling: spin-momentum locking and real-space magnetization switching.

Identification of thermodynamically stable compounds for experimental testing.

Establishment of general design principles for nonvolatile ME effects.

Abstract

We present a comprehensive theoretical investigation of magnetoelectric (ME) coupling mechanisms in 19 altermagnetic and 4 ferrimagnetic Type-I multiferroics using electronic band structure calculations with spin-orbit coupling, a first-principles ME response framework, and spin-space-group theory analysis. We formulate a universal scheme for realizing nonvolatile ME coupling in Type-I multiferroics, where two distinct pathways emerge, each dictated by spin-space symmetry. The first pathway is associated with switching of the spin splitting or the now familiar spin-momentum locking in reciprocal space, characteristic of some altermagnetic mul-tiferroics that exhibit coexisting antiferromagnetism and ferroelectricity. The second pathway involves real-space magnetization switching via electric polarization reversal, characterized by switchable components of the linear ME tensor, despite the traditionally weak coupling in Type-I systems due to the independent origins of magnetism and ferroelectricity. We demonstrate that these two intrinsic ME coupling mechanisms are mutually exclusive and propose thermodynami-cally stable compounds for experimentation. Our findings establish general design principles for controlling robust nonvolatile ME effects in multiferroic materials.