At ambient pressure and zero field, tetragonal CeAuSb2 hosts stripe antiferromagnetic order at TN=6.3 K. Here we first show via bulk thermodynamic probes and x-ray diffraction measurements that this magnetic order is connected with a structural phase transition to a superstructure which likely breaks C4 symmetry, thus signaling nematic order. The temperature-field-pressure phase diagram of CeAuSb2 subsequently reveals the emergence of additional ordered states under applied pressure at a multicritical point. Our phenomenological model supports the presence of a vestigial nematic phase in CeAuSb2 akin to iron-based high-temperature superconductors; however, superconductivity, if present, remains to be discovered.
@article{arxiv.1908.07649,
title = {Nematic state in CeAuSb$_{2}$},
author = {S. Seo and Xiaoyu Wang and S. M. Thomas and M. C. Rahn and D. Carmo and F. Ronning and E. D. Bauer and R. D. dos Reis and M. Janoschek and J. D. Thompson and R. M. Fernandes and P. F. S. Rosa},
journal= {arXiv preprint arXiv:1908.07649},
year = {2020}
}