Tracking the nematicity in cuprate superconductors: a resistivity study under uniaxial pressure

TL;DR

This study investigates nematicity in hole-doped cuprates through resistivity measurements under uniaxial pressure, revealing potential nematic transitions linked to the pseudogap state, with implications for understanding high-temperature superconductivity.

Contribution

It provides experimental evidence of nematic behavior in cuprates using elastoresistivity, highlighting differences across doping levels and suggesting nematic order as an electronic phase within the pseudogap.

Findings

Nematic transition temperature $T_{k}$ coincides with pseudogap temperature $T^*$ near optimal doping.

Resistivity slope $ ext{zeta}$ shows Curie-Weiss behavior above $T_{k}$.

Nematic order may be an electronic phase within the pseudogap state.

Abstract

Overshadowing the superconducting dome in hole-doped cuprates, the pseudogap state is still one of the mysteries that no consensus can be achieved. It has been suggested that the rotational symmetry is broken in this state and may result in a nematic phase transition, whose temperature seems to coincide with the onset temperature of the pseudogap state $T^*$ around optimal doping level, raising the question whether the pseudogap results from the establishment of the nematic order. Here we report results of resistivity measurements under uniaxial pressure on several hole-doped cuprates, where the normalized slope of the elastoresistivity $\zeta$ can be obtained as illustrated in iron-based superconductors. The temperature dependence of $\zeta$ along particular lattice axis exhibits kink feature at $T_{k}$ and shows Curie-Weiss-like behavior above it, which may suggest a spontaneous nematic transition. While $T_{k}$ seems to be the same as $T^*$ around the optimal doping and in the overdoped region, they become very different in underdoped La$_{2-x}$Sr$_{x}$CuO$_4$. Our results suggest that the nematic order, if indeed existing, is an electronic phase within the pseudogap state.