Hidden Real Topology and Unusual Magnetoelectric Responses in Two-Dimensional Antiferromagnets

Jialin Gong, Yang Wang, Yilin Han, Zhenxiang Cheng*, Xiaotian Wang*, Zhi Ming Yu, Yugui Yao*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)

Abstract

Recently, the real topology has been attracting widespread interest in two dimensions (2D). Here, based on first-principles calculations and theoretical analysis, the monolayer Cr2Se2O (ML-CrSeO) is revealed as the first material example of a 2D antiferromagnetic (AFM) real Chern insulator (RCI) with topologically protected corner states. Unlike previous RCIs, it is found that the real topology of the ML-CrSeO is rooted in one certain mirror subsystem of the two spin channels, and cannot be directly obtained from all the valence bands in each spin channel as commonly believed. In particular, due to antiferromagnetism, the corner modes in ML-CrSeO exhibit strong corner-contrasted spin polarization, leading to spin–corner coupling (SCC). This SCC enables a direct connection between spin space and real space. Consequently, large and switchable net magnetization can be induced in the ML-CrSeO nanodisk by electrostatic means, such as potential step and in-plane electric field, and the corresponding magnetoelectric responses behave like a sign function, distinguished from that of the conventional multiferroic materials. This work considerably broadens the candidate range of RCI materials, and opens up a new direction for topo-spintronics and 2D AFM materials research.

Original languageEnglish
Article number2402232
JournalAdvanced Materials
Volume36
Issue number29
DOIs
Publication statusPublished - 18 Jul 2024

Keywords

  • antiferromagnets
  • hidden real topology
  • spin–corner coupling
  • two dimensions
  • unusual magnetoelectric responses

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