Superconductivity in compensated and uncompensated semiconductors

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Physics

Background:

• Investigating superconductivity in heavily doped semiconductors is crucial for understanding novel electronic properties.
• The interplay between disorder, doping, and superconductivity presents significant theoretical challenges.

Purpose of the Study:

• To investigate the localization and superconductivity phenomena in heavily doped semiconductors.
• To describe the crossover from host band to impurity band superconductivity using a theoretical model.

Main Methods:

• Utilized the disordered three-dimensional attractive Hubbard model for binary alloys.
• Incorporated microscopic inhomogeneity and thermal superconducting fluctuations via self-consistent 1-loop order theory.

Main Results:

• Observed a superconductor-insulator transition accompanying the host-to-impurity band crossover.
• Identified an enhancement of the critical temperature (Tc) around the crossover region.
• Demonstrated that further electron localization leads to Cooper pair localization, pseudogap formation, and suppression of superconductivity by doping compensation or carrier increase.

Conclusions:

• The study provides a theoretical framework for understanding superconductivity in doped semiconductors, including materials like boron-doped diamond, SiC, and Si.
• Doping strategies significantly impact superconducting properties, with compensation and carrier increases generally suppressing superconductivity.