Charge Density Waves in YBa_{2}Cu_{3}O_{6.67} Probed by Resonant X-Ray Scattering under Uniaxial Compression

Area of Science:

• Condensed matter physics
• Materials science
• Superconductivity

Background:

• High-temperature superconductors like YBa_{2}Cu_{3}O_{6.67} exhibit complex electronic phases.
• Understanding charge correlations is crucial for elucidating superconductivity mechanisms.

Purpose of the Study:

• Investigate the impact of uniaxial compression on charge correlations in YBa_{2}Cu_{3}O_{6.67}.
• Determine the dimensionality and anisotropy of charge order under strain.

Main Methods:

• Cu L_{3}-edge resonant x-ray scattering (RXS) on single crystals.
• Application of uniaxial stress along Cu─O─Cu bond directions (a and b).

Main Results:

• Confirmed strong in-plane anisotropy of 2D charge correlations.
• Observed symmetric response: pressure along 'a' enhances correlations along 'b', and vice versa.
• 3D long-range charge order emerged along 'b' under compression along 'a'.

Conclusions:

• The results imply a uniaxial order parameter for charge correlations.
• 3D charge order is confined to CuO_{2} planes, suggesting it's a general feature in cuprates.
• Provides insights into electronic nematicity and charge order-superconductivity interplay.