The recent discoveries of ferroelectric metal and Weyl semimetal (WSM) have stimulated a natural question: whether these two exotic states of matter can coexist in a single material or not. These two discoveries ensure us that physically it is possible since both of them share the same necessary condition, the broken inversion symmetry. Here, by using first-principles calculations, we demonstrate that the experimentally synthesized nonmagnetic HgPbO3 represents a unique example of such hybrid "\emph{Weyl ferroelectric semimetal}". Its centrosymmetric R3ˉc phase will undergo a ferroelectric phase transition to the ferroelectric R3c structure. Both phases are metallic and the ferroelectric phase owns a spontaneous polarization of 33 μC/cm2. Most importantly, it also harbors six pairs of chiral Weyl nodes around the Fermi level to be an oxide WSM. The structural symmetry broken phase transition induces a topological phase transition. The coexistence of ferroelectricity and Weyl nodes in HgPbO3 is an ideal platform for exploring multiphase interaction and mutual control. The Weyl nodes can be tuned by external pulse electric field, which is promising for potential applications of integrated topotronic and ferroelectric devices.
@article{arxiv.1610.07142,
title = {Weyl Ferroelectric Semimetal},
author = {Ronghan Li and Yuanfeng Xu and Jianggang He and Sami Ullah and Jiangxiu Li and Jun-Ming Liu and Dianzhong Li and Cesare Franchini and Hongming Weng and Xing-Qiu Chen},
journal= {arXiv preprint arXiv:1610.07142},
year = {2016}
}