Double-leaf Riemann surface topological converse magnetoelectricity

TL;DR

This paper introduces a topological concept in multiferroics, revealing a double-leaf Riemann-surface mechanism in GdI₂ monolayer that enables dissipationless electric control of magnetism, promising for energy-efficient devices.

Contribution

It presents a novel topological framework for magnetoelectricity in 2D materials, demonstrating robust electric control of magnetization via a double-leaf Riemann surface mechanism.

Findings

Topological magnetoelectricity in GdI₂ monolayer achieved.

Electric cycle induces 180° spin reversal.

Potential for designing new topological magnetoelectric materials.

Abstract

Electric field control of magnetism in solids, i.e. the converse magnetoelectricity, is highly desired for applications of scalable energy-efficient logic devices. However, it is not only a technical challenge but also a scientific paradox, since in principle the electric and magnetic degrees of freedom obey distinct rules of symmetries. Despite the great progresses obtained in the community of multiferroics during the past decades, the success of magnetoelectricity remains on its way and more alternative approaches with conceptual revolution are urgently needed. Here, by introducing the concept of topology into multiferroics, an exotic magnetoelectric double-leaf Riemann-surface is unveiled based on the mechanism of spin-dependent $d-p$ hybridization in a two-dimensional magnet: GdI$_2$ monolayer. Protected by the topology, a $180^\circ$ spin reversal can be precisely achieved by an electric cycle, leading to a robust and dissipationless converse magnetoelectric function. Such a topological magnetoelectricity allows the nontrivial manipulation of magnetization by AC electric field. In this category, more candidate materials with better performance are designed targetedly, which pave the road to the potential applications with topological magnetoelectrics.