Two-Dimensional Superconducting Fluctuations Associated with Charge-Density-Wave Stripes in...

Area of Science:

• Condensed Matter Physics
• Materials Science
• Superconductivity

Background:

• Lanthanum strontium cuprate (La_{1.87}Sr_{0.13}Cu_{0.99}Fe_{0.01}O_{4}) exhibits complex interplay between superconductivity and density wave orders.
• In-plane Fe doping is known to enhance spin density wave (SDW) and charge density wave (CDW) order while suppressing superconducting transition temperature (T_{c}).

Purpose of the Study:

• To investigate the impact of Fe doping on superconducting correlations in La_{1.87}Sr_{0.13}Cu_{0.99}Fe_{0.01}O_{4}.
• To explore the relationship between density wave order and the emergence of a novel superconducting state.
• To identify the critical conditions for the formation of pair density wave (PDW) order.

Main Methods:

• Resonant soft x-ray scattering (RSXS) was employed to probe electronic order.
• Analysis of superconducting correlations and their association with CDW stripe order.

Main Results:

• Fe doping induces highly two-dimensional superconducting correlations, a potential signature of pair density wave (PDW) order.
• The emergence of PDW signatures is strongly associated with the CDW stripe.
• PDW signatures appear when the CDW stripe correlation length exceeds approximately eight lattice units (∼8a).

Conclusions:

• Fe doping in La_{1.87}Sr_{0.13}Cu_{0.99}Fe_{0.01}O_{4} facilitates the formation of two-dimensional superconducting correlations.
• The study establishes a direct link between CDW stripe order and the onset of PDW order.
• A correlation length of the CDW stripe greater than ∼8a is identified as a critical condition for PDW formation.