Superconducting gap structure of the 115s revisited

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Heavy fermion superconductors, particularly those in the 115 family (e.g., Ce- and Pu-based compounds), exhibit complex electronic behaviors.
• Antiferromagnetic ordering often coexists with superconductivity in these materials, suggesting a strong interplay between magnetism and the superconducting state.

Purpose of the Study:

• To investigate the electronic structure of Ce- and Pu-based heavy fermion superconductors using first-principles calculations.
• To determine the most favorable superconducting order parameters by analyzing the gap equation with a pairing interaction relevant to antiferromagnetic ordering.

Main Methods:

• Utilizing density functional theory (DFT) to compute the electronic structure of 115-family heavy fermion superconductors.
• Employing the gap equation to model superconducting pairing interactions, specifically considering a wavevector (π, π, qz) associated with antiferromagnetism.

Main Results:

• The study provides evidence supporting the commonly accepted dx2−y2 superconducting order parameter.
• An extended s-wave order parameter, characterized by the presence of nodes, is found to be a plausible alternative or coexisting state.

Conclusions:

• The theoretical findings suggest that superconductivity in these heavy fermion systems may involve multiple or unconventional order parameters.
• Further experimental measurements are proposed to experimentally distinguish between the dx2−y2 and extended s-wave scenarios, aiding in understanding the fundamental mechanisms of superconductivity.