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Nematicity is a many-body quantum phase that breaks rotational symmetry while preserving translational symmetry. It has been discovered in the phase diagrams of both iron-based and cuprate high-temperature superconductors [1-3]. In the iron-based superconductors, the optimal doping of the superconducting phase coincides with the putative nematic quantum critical point, suggesting the possibility of superconducting pairing enhanced by nematic quantum fluctuations [2,4]. However, a comprehensive study of the nematic fluctuations is still absent in the BaFe₂(As_1-xP_x)₂, which exhibits the cleanest signature of quantum criticality among all the iron-based superconductors. In this talk, I will present a detailed study of the nematic fluctuations of BaFe₂(As_1-xP_x)₂ using the elastoresistivity measurement. I will also present the study of strain dependence of superconducting Tc, which shed light on the intricate relations between nematicity and superconductivity.

Reference:
[1] J.-H. Chu, et. al., Science 329, 824 (2010)
[2] J.-H. Chu, et. al., Science 337, 710 (2012)
[3] Y. Sato, et. al., Nat. Phy. 13, 1074 (2017)
[4] H.-H. Kuo, et. al., Science 352, 958 (2016)