Deng Jinghao, Guo Deping, Wen Yao, Lu Shuangzan, Zhang Hui, Cheng Zhengbo, Pan Zemin, Jian Tao, Li Dongyu, Wang Hao, Bai Yusong, Li Zhilin, Ji Wei, He Jun, Zhang Chendong
School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China.
College of Physics and Electronic Engineering, Center for Computational Sciences, Sichuan Normal University, Chengdu 610101, China.
Sci Adv. 2025 Mar 7;11(10):eado6538. doi: 10.1126/sciadv.ado6538. Epub 2025 Mar 5.
A reduced dimensionality of multiferroic materials is highly desired for device miniaturization, but the coexistence of ferroelectricity and magnetism at the two-dimensional limit is yet to be conclusively demonstrated. Here, we used a NbSe substrate to break both the rotational and inversion symmetries in monolayer VCl and, thus, introduced exceptional in-plane ferroelectricity into a two-dimensional magnet. Scanning tunneling spectroscopy directly visualized ferroelectric domains and manipulated their domain boundaries in monolayer VCl, where coexisting antiferromagnetic order with canted magnetic moments was verified by vibrating sample magnetometer measurements. Our density functional theory calculations highlight the crucial role that highly directional interfacial Cl-Se interactions play in breaking the symmetries and, thus, in introducing in-plane ferroelectricity, which was further verified by examining an ML-VCl/graphene sample. Our work demonstrates an approach to manipulate the ferroelectric states in monolayered magnets through van der Waals interfacial interactions.
为了实现器件小型化，多铁性材料的维度降低是非常必要的，但是铁电性和磁性在二维极限下的共存尚未得到最终证实。在此，我们使用NbSe衬底打破了单层VCl中的旋转对称性和反演对称性，从而在二维磁体中引入了异常的面内铁电性。扫描隧道光谱直接可视化了单层VCl中的铁电畴，并操纵了它们的畴界，通过振动样品磁强计测量验证了其中共存的具有倾斜磁矩的反铁磁序。我们的密度泛函理论计算突出了高度定向的界面Cl-Se相互作用在打破对称性以及引入面内铁电性方面所起的关键作用，通过研究ML-VCl/石墨烯样品进一步证实了这一点。我们的工作展示了一种通过范德华界面相互作用来操纵单层磁体中铁电态的方法。
