Polarons are physical objects of material science that are hard to capture from first-principles calculations. ${\mathrm{WO}}_3$ is a paradigmatic system to study polarons and here we present calculations of a single self-trapped single polaron in ${\mathrm{WO}}_3$ from density functional theory calculations. Our calculations show that the single polaron is at a higher energy than the fully delocalized solution, in agreement with the experiments where a single polaron is an excited state of ${\mathrm{WO}}_3$. The symmetry-adapted mode decomposition of the polaron distortions shows that, among numerous modes, a polar zone center mode has the largest contribution and can be at the origin of the observed weak ferroelectricity of ${\mathrm{WO}}_3$.

• Received 25 October 2019
• Accepted 7 February 2020

DOI:https://doi.org/10.1103/PhysRevResearch.2.012052

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Published by the American Physical Society