The interplay between ferroelectricity and band topology can give rise to a wide range of both fundamental and applied research. Here, we map out the emergence of nontrivial corner states in two-dimensional ferroelectrics, and remarkably demonstrate that ferroelectricity and corner states are coupled together by crystallographic symmetry to realize the electric control of higher-order topology. Implemented by density functional theory, we identify a series of experimentally synthesized two-dimensional ferroelectrics, such as In2Se3, BN bilayers, and SnS, as realistic material candidates for the proposed ferroelectric higher-order topological insulators. Our work not only sheds new light on traditional ferroelectric materials but also opens an avenue to bridge the higher-order topology and ferroelectricity that provides a nonvolatile handle to manipulate the topology in next-generation electronic devices.
@article{arxiv.2211.04121,
title = {Ferroelectric higher-order topological insulator in two dimensions},
author = {Ning Mao and Runhan Li and Xiaorong Zou and Ying Dai and Baibiao Huang and Chengwang Niu},
journal= {arXiv preprint arXiv:2211.04121},
year = {2023}
}