Emergence of superconductivity in heavy-electron materials.

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Unconventional superconductivity in heavy-electron materials is linked to spin fluctuations near magnetic quantum critical points.
• Existing models do not adequately describe the superconducting transition temperature (Tc) in these materials, unlike the Bardeen, Cooper, and Schrieffer (BCS) theory for conventional superconductors.

Purpose of the Study:

• To propose a phenomenological model for the superconducting transition temperature (Tc) in heavy-electron materials.
• To provide a BCS-like expression for Tc based on spin-fluctuation interactions and heavy-electron normal state properties.

Main Methods:

• Developed a simplified model for the effective range and strength of spin-fluctuation-induced quasiparticle interactions.
• Applied the model to understand pressure-induced variations in Tc for specific heavy-electron compounds.

Main Results:

• The proposed model quantitatively explains pressure-dependent Tc variations in CeCoIn5 and CeRhIn5.
• It predicts universal scaling behavior and a dome-like Tc structure for quantum critical heavy-electron superconductors.
• The model reveals connections between different heavy-electron superconductor families and quantifies Tc variations with a single parameter.

Conclusions:

• The new model offers a unified understanding of unconventional superconductivity in heavy-electron materials.
• It successfully describes the emergence of superconductivity from the heavy-electron normal state.
• The model provides a powerful tool for predicting and analyzing superconducting properties in this class of materials.