First principles based proximity effect of superconductor-normal metal heterostructures

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Mechanics

Background:

• Superconductor-normal metal heterostructures exhibit unique electronic properties due to the proximity effect.
• Understanding this effect is crucial for developing advanced electronic devices.

Purpose of the Study:

• To investigate the proximity effect in superconductor-normal metal heterostructures.
• To analyze the relationship between the superconducting order parameter and the anomalous spectral function.
• To elucidate the role of Andreev scattering in the proximity effect.

Main Methods:

• First-principles calculations were employed.
• Kohn-Sham-Bogoliubov-de Gennes equations were solved using the Screened Korringa-Kohn-Rostoker method.
• The pairing potential was treated as an adjustable parameter.

Main Results:

• The superconducting order parameter and layer-resolved anomalous spectral function were calculated for an Au/Nb(001) system.
• The anomalous spectral function exhibits characteristics of Andreev scattering.
• A direct connection between the anomalous spectral function and the electron-hole ratio of quasiparticle states was established.

Conclusions:

• The anomalous spectral function serves as a key indicator for understanding the proximity effect.
• Andreev scattering plays a significant role in the observed phenomena.
• This work provides a detailed microscopic understanding of proximity effects in heterostructures.