Nematicity in stripe ordered cuprates probed via resonant x-ray scattering

TL;DR

This study uses resonant x-ray scattering to investigate electronic nematicity in stripe-ordered cuprates, revealing it as a distinct order parameter enhanced by charge density wave formation, separate from structural order.

Contribution

It demonstrates that electronic nematicity in stripe-ordered cuprates is an intrinsic order parameter, distinct from structural order, and is influenced by charge density wave onset.

Findings

Electronic nematicity is enhanced by CDW order.

Structural and electronic orders have different temperature dependences.

Nematicity is identified as a separate order parameter.

Abstract

In underdoped cuprate superconductors, a rich competition occurs between superconductivity and charge density wave (CDW) order. Whether rotational symmetry breaking (nematicity) occurs intrinsically and generically or as a consequence of other orders is under debate. Here we employ resonant x-ray scattering in stripe-ordered (La,M)_2CuO_4 to probe the relationship between electronic nematicity of the Cu 3d orbitals, structure of the (La,M)_2O_2 layers, and CDW order. We find distinct temperature dependences for the structure of the (La,M)_2O_2 layers and the electronic nematicity of the CuO_2 planes, with only the latter being enhanced by the onset of CDW order. These results identify electronic nematicity as an order parameter that is distinct from a purely structural order parameter in underdoped striped cuprates.