Competing striped structures in La2CuO4+y

TL;DR

This paper investigates the nanoscale spatial arrangements of structural defects in La2CuO4+y using advanced microscopy, revealing incommensurate ripples that are anticorrelated with dopant puddles, shedding light on inhomogeneity in high-temperature superconductors.

Contribution

It introduces the use of scanning nano X-ray diffraction to map nanoscale lattice distortions and dopant distributions in cuprates, revealing their spatial competition.

Findings

Local lattice distortions form incommensurate ripples.

Distortions are spatially anticorrelated with dopant puddles.

Nanoscale inhomogeneity influences superconducting properties.

Abstract

High temperature superconductivity emerges in unique materials, like cuprates, that belong to the class of heterostructures at atomic limit, made of a superlattice of superconducting atomic layers intercalated by spacer layers. The physical properties of a strongly correlated electronic system, emerge from the competition between different phases with a resulting inhomogeneity from nanoscale to micron scale. Here we focus on the spatial arrangements of two types of structural defects in the cuprate La2CuO4+y : i) the local lattice distortions in the CuO2 active layers and ii) the lattice distortions around the charged chemical dopants in the spacer layers. We use a new advanced microscopy method: scanning nano X-ray diffraction (nXRD). We show here that local lattice distortions form incommensurate nanoscale ripples spatially anticorrelated with puddles of self-organized chemical dopants in the spacer layers.