Charge order in La_{1.8-x}Eu_{0.2}Sr_xCuO_4 studied by resonant soft X-ray diffraction

TL;DR

This study uses resonant soft X-ray scattering to investigate charge ordering in La_{1.8-x}Eu_{0.2}Sr_xCuO_4, revealing doping-dependent charge stripes that precede spin order, indicating charge order as a key driver of stripe phases.

Contribution

It provides detailed experimental evidence of charge ordering and its relation to doping and temperature in a cuprate superconductor, highlighting charge order as a primary factor in stripe formation.

Findings

Charge order wave vector varies with doping.

Charge order occurs above spin ordering temperature.

High hole concentration detected in stripes.

Abstract

Resonant soft X-ray scattering with photon energies near the O K and the Cu L3 edges was used to study charge ordering in the system La_{1.8-x}Eu_{0.2}Sr_xCuO_4 as a function of temperature for x = 0.125 and 0.15. From the superstructure diffraction intensities a charge ordering with a doping dependent wave vector is derived which is in this system well below the transition temperature of the low-temperature tetragonal phase but well above the onset of spin ordering. This indicates that charge ordering is the primary driving force for the formation of stripe-like phases in two-dimensional doped cuprates. Analysis of the lineshape of the scattered intensity as a function of photon energy yields evidence for a high hole concentration in the stripes.