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arXiv · 2202.00077

Absence of nematic instability in LiFeAs

Michael Wissmann·Federico Caglieris·Xiaochen Hong·Saicharan Aswartham·Anna Vorobyova·Igor Morozov·Bernd Büchner·Christian Hess
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Abstract

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.

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Michael Wissmann, Federico Caglieris, Xiaochen Hong, Saicharan Aswartham, Anna Vorobyova, Igor Morozov, Bernd Büchner, Christian Hess. 2022-01-31. Absence of nematic instability in LiFeAs. https://doi.org/10.1103/physrevb.106.054508

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