The identification of electronic nematicity across series of iron-based superconductors raises the question of its relationship with superconductivity and other ordered states. Here, we report a systematic elastoresistivity study on LaFe1−xCoxAsO single crystals, which have well separated structural and magnetic transition lines. All crystals show Curie-Weiss-like nematic susceptibility in the tetragonal phase. The extracted nematic temperature is monotonically suppressed upon cobalt doping, and changes sign around the optimal doping level, indicating a possible nematic quantum critical point beneath the superconducting dome. The amplitude of nematic susceptibility shows a peculiar double-peak feature. This could be explained by a combined effect of different contributions to the nematic susceptibility, which are amplified at separated doping levels of LaFe1−xCoxAsO.
@article{arxiv.1908.00484,
title = {Evolution of the nematic susceptibility in LaFe$_{1-x}$Co$_x$AsO},
author = {Xiaochen Hong and Federico Caglieris and Rhea Kappenberger and Sabine Wurmehl and Saicharan Aswartham and Francesco Scaravaggi and Piotr Lepucki and Anja U. B. Wolter and Hans-Joachim Grafe and Bernd Büchner and Christian Hess},
journal= {arXiv preprint arXiv:1908.00484},
year = {2020}
}