Tuning the Pairing Interaction in a d-Wave Superconductor by Paramagnons Injected through Interfaces

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Unconventional superconductivity and magnetism are fundamentally linked in many materials.
• Understanding their microscopic interplay is crucial for developing new quantum technologies.

Purpose of the Study:

• To investigate the influence of magnetic fluctuations on superconductivity at interfaces.
• To explore the tuning of superconducting properties in hybrid heterostructures.

Main Methods:

• Fabrication of hybrid superlattices using CeCoIn_{5} (superconductor) and CeRhIn_{5} (antiferromagnetic metal).
• Application of pressure to suppress antiferromagnetic order.
• Analysis of upper critical fields to probe superconducting properties.

Main Results:

• Superconducting and antiferromagnetic states coexist in spatially separated layers.
• Interface coupling significantly modifies superconducting properties.
• Suppression of antiferromagnetism induces an extreme strong-coupling nature in superconducting electron pairs.

Conclusions:

• Superconducting pairing can be effectively tuned by magnetic fluctuations (paramagnons) transmitted across interfaces.
• This work highlights a novel mechanism for controlling superconductivity via magnetism in engineered heterostructures.