When the atomic layers in a non-centrosymmetric van der Waals structure slide against each other, the interfacial charge transfer results in a reversal of the structures spontaneous polarization. This phenomenon is known as sliding ferroelectricity and it is markedly different from conventional ferroelectric switching mechanisms relying on ion displacement. Here, we present layer dependence as a new dimension to control sliding ferroelectricity. By fabricating 3R MoS2 of various thicknesses into dual-gate field-effect transistors, we obtain anomalous intermediate polarization states in multilayer 3R MoS2. Using results from ab initio density functional theory calculations, we propose a generalized model to describe the ferroelectric switching process in multilayer 3R MoS2 and to explain the formation of these intermediate polarization states. This work reveals the critical roles that layer number and interlayer dipole coupling play in sliding ferroelectricity and presents a new strategy for the design of novel sliding ferroelectric devices.
@article{arxiv.2211.05277,
title = {Sliding induced multiple polarization states in two-dimensional ferroelectrics},
author = {Peng Meng and Yaze Wu and Renji Bian and Er Pan and Biao Dong and Xiaoxu Zhao and Jiangang Chen and Lishu Wu and Yuqi Sun and Qundong Fu and Qing Liu and Dong Shi and Qi Zhang and Yong-Wei Zhang and Zheng Liu and Fucai Liu},
journal= {arXiv preprint arXiv:2211.05277},
year = {2022}
}