Engineering valley index is essential and highly sought for valley physics, but currently it is exclusively based on the paradigm of the challenging ferrovalley with spin-orientation reversal under magnetic field. Here, an alternative strategy, i.e., the so-called ferroelectrovalley, is proposed to tackle the insurmountable spin-orientation reversal, which reveres valley index with the feasible ferroelectricity. Using symmetry arguments and tight-binding model, the C_2 rotation is unveiled to be able to take the place of time reversal for operating valley index in two-dimensional multiferroic kagome lattices, which enables the ferroelectricity-engineered valley index, thereby generating the concept of ferroelectrovalley. Based on first-principles calculations, this concept is further demonstrated in the breathing kagome lattice of single-layer Ti3Br8, wherein ferroelectricity couples the breathing process. These findings open a new direction for valleytronics and two-dimensional materials research.
@article{arxiv.2404.08988,
title = {Ferroelectrovalley in Two-Dimensional Multiferroic Lattices},
author = {Jiangyu Zhao and Yangyang Feng and Ying Dai and Baibiao Huang and Yandong Ma},
journal= {arXiv preprint arXiv:2404.08988},
year = {2024}
}