The relationship between unconventional superconductivity, antiferromagnetism and nematic order in iron-based superconductors (FeSCs) is still highly debated. In many FeSCs superconductivity is in proximity of a nematically and magnetically ordered state. LiFeAs is an exceptional stoichiometric FeSC becoming superconducting below 18 K, without undergoing a structural or magnetic transition. However, some recent experimental studies suggested the existence of finite nematic fluctuations and even a nematic superconducting state. In this study, we employ elastoresistance as a measure of nematic fluctuations in pristine LiFeAs and compare the findings with the elastoresistance of LiFeAs at low Co and V doping levels as well with that of magnetically and nematically ordering NaFeAs. We find LiFeAs and cobalt-doped LiFeAs far away from a nematic instability.
@article{arxiv.2202.00077,
title = {Absence of nematic instability in LiFeAs},
author = {Michael Wissmann and Federico Caglieris and Xiaochen Hong and Saicharan Aswartham and Anna Vorobyova and Igor Morozov and Bernd Büchner and Christian Hess},
journal= {arXiv preprint arXiv:2202.00077},
year = {2022}
}