Download file (3.66MB)
Download as zip (3.23MB)

コレクション

引用

説明:

Ferroelectricity is intriguing for its spontaneous electric polarization, which is switchable by an external electric field. Expanding ferroelectric materials to two-dimensional limit will provide versatile applications for the development of next-generation nonvolatile devices [1-3]. Conventional ferroelectricity requires the materials consisting of at least two constituent elements associated with polar crystalline structures. Monolayer graphene as an elementary two-dimensional material unlikely exhibits ferroelectric order due to its highly centrosymmetric hexagonal lattices. Nevertheless, two-dimensional moiré superlattices offer a powerful way to engineer diverse electronic orders in non-polar materials [4-7]. Here, we report the observations of electronic ferroelectricity in monolayer graphene by introducing asymmetric moiré superlattice at the graphene/h-BN interface. Utilizing Hall measurements, the electric polarization is identified to stem from electron-hole dipoles, suggesting the electronic dynamics of the observed ferroelectricity. Standard polarization-electric field hysteresis loops, as well as unconventional multiple switchable polarization states, have been achieved. By in-situ comparing with control devices, we found that the electronic ferroelectricity in graphene moiré systems is independent of layer number of graphene and the corresponding fine band structures. Furthermore, we demonstrate the applications of this ferroelectric moiré structures in multi-state non-volatile data storage and the emulation of versatile synaptic behaviors, including short-term plasticity, long-term potentiation and long-term depression. This work not only enriches the fundamental understanding of ferroelectricity, but also demonstrates the promising applications of graphene in multi-state memories and neuromorphic computing.

権利情報:

• Creative Commons BY Attribution 4.0 International
  

キーワード: Ferroelectric materials, monolayer graphene, moiré superlattice

刊行年月日: 2024-12-30

出版者: Springer Science and Business Media LLC

掲載誌:

• Nature Communications (ISSN: 20411723) vol. 15 issue. 1 10905

研究助成金:

• National Natural Science Foundation of China 12274354
• Natural Science Foundation of Zhejiang Province XHD23A2001
• Natural Science Foundation of Zhejiang Province LR24A040003
• Natural Science Foundation of Zhejiang Province ZJ2023077

原稿種別: 出版者版 (Version of record)

MDR DOI:

公開URL: https://doi.org/10.1038/s41467-024-55281-z

関連資料:

その他の識別子:

連絡先:

更新時刻: 2025-02-05 12:31:45 +0900

MDRでの公開時刻: 2025-02-05 12:31:45 +0900