Microscopic origin of multiferroic order in monolayer NiI2

Loading...
Thumbnail Image

Access rights

openAccess
publishedVersion

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2022-04-01

Major/Subject

Mcode

Degree programme

Language

en

Pages

7

Series

2D Materials, Volume 9, issue 2, pp. 1-7

Abstract

The discovery of multiferroic behavior in monolayer NiI2 provides a new symmetry-broken state in van der Waals monolayers, featuring the simultaneous emergence of helimagnetic order and ferroelectric order at a critical temperature of T = 21 K. However, the microscopic origin of multiferroic order in NiI2 monolayer has not been established, and in particular, the role of non-collinear magnetism and spin–orbit coupling in this compound remains an open problem. Here we reveal the origin of the two-dimensional multiferroicity in NiI2 using first-principles electronic structure methods. We show that the helimagnetic state appears as a consequence of the long-range magnetic exchange interactions, featuring sizable magnetic moments in the iodine atoms. We demonstrate that the electronic density reconstruction accounting for the ferroelectric order emerges from the interplay of non-collinear magnetism and spin–orbit coupling. We demonstrate that the ferroelectric order is controlled by the iodine spin–orbit coupling, and leads to an associated electronically-driven distortion in the lattice. Our results establish the microscopic origin of the multiferroic behavior in monolayer NiI2, putting forward the coexistence of helical magnetic order and ligand spin–orbit coupling as driving forces for multiferroic behavior in two-dimensional materials.

Description

Kustantaja tarjonnut takautuvaa avoimuutta IOP:n uuden sopimuksen nimissä -> vaihda OA-tyyppi ja tallenna OA-julkaisu

Keywords

Other note

Citation

Otero Fumega, A & Lado, J 2022, ' Microscopic origin of multiferroic order in monolayer NiI2 ', 2D Materials, vol. 9, no. 2, 025010, pp. 1-7 . https://doi.org/10.1088/2053-1583/ac4e9d