A Room-Temperature Ferroelectric Semimetal

Authors

Pankaj Sharma, University of New South WalesFollow
Fei-Xiang Xiang, University of New South WalesFollow
Ding-Fu Shao, University of Nebraska - LincolnFollow
Dawei Zhang, University of New South Wales
Evgeny Y. Tsymbal, University of Nebraska - LincolnFollow
Alex R. Hamilton, University of New South WalesFollow
Jan Seidel, University of New South WalesFollow

Date of this Version

7-5-2019

Citation

Science Advances 5, eaax5080 (2019).

DOI: 10.1126/sciadv.aax5080

Comments

© 2019 the authors. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).

Abstract

Coexistence of reversible polar distortions and metallicity leading to a ferroelectric metal, first suggested by Anderson and Blount in 1965, has so far remained elusive. Electrically switchable intrinsic electric polarization, together with the direct observation of ferroelectric domains, has not yet been realized in a bulk crystalline metal, although incomplete screening by mobile conduction charges should, in principle, be possible. Here, we provide evidence that native metallicity and ferroelectricity coexist in bulk crystalline van der Waals WTe2 by means of electrical transport, nanoscale piezoresponse measurements, and first-principles calculations. We show that, despite being a Weyl semimetal, WTe2 has switchable spontaneous polarization and a natural ferroelectric domain structure at room temperature. This new class of materials has tantalizing potential for functional nanoelectronics applications.