Spatially inhomogeneous competition between superconductivity and the charge density wave in YBa₂Cu₃O_6.67

Area of Science:

• Condensed Matter Physics
• Materials Science
• Superconductivity

Background:

• High-temperature superconductors like YBCO exhibit complex charge density wave (CDW) order.
• Two distinct CDW ordering tendencies, ferro- (F-CDW) and antiferro- (AF-CDW), have been identified based on c-axis correlations.
• Fundamental questions remain regarding the interplay between these competing orders and superconductivity.

Purpose of the Study:

• To investigate the impact of F-CDW and AF-CDW correlations on superconductivity in YBCO.
• To determine if either CDW order is responsible for electronic reconstruction.
• To elucidate the relationship between CDW order and the superconducting state.

Main Methods:

• X-ray diffraction was employed to study YBCO (YBa2Cu3O7-x) samples.
• Experiments were conducted under varying magnetic field and temperature conditions.
• Correlation lengths of F-CDW and AF-CDW were compared.

Main Results:

• Regions with F-CDW correlations exhibit a stronger suppression of superconductivity compared to AF-CDW regions.
• An inhomogeneous superconducting state is implied, with some regions displaying fragile superconductivity.
• F-CDW ordering possesses long-range characteristics, sufficient to alter the electronic structure.

Conclusions:

• F-CDW correlations significantly impact both superconducting and normal state properties of YBCO.
• The findings suggest that F-CDW ordering plays a crucial role in the electronic reconstruction of the material.
• The study highlights the inhomogeneous nature of superconductivity in the presence of competing charge density wave orders.