Quantum Coherence of Electrons Field-Emitted from a Superconductor: Correlations and Entanglement

TL;DR

This paper analyzes electron correlations and entanglement in field-emitted electrons from a superconductor, proposing experiments to observe Bell inequality violations and clarifying the role of Andreev processes.

Contribution

It introduces a detailed analysis of electron correlations and entanglement in superconductor-emitted electrons, with analytical formulas and experimental proposals.

Findings

Electrons emitted in opposite directions show positive correlations.

Electrons can be entangled and violate Bell's inequality.

Andreev processes are crucial for understanding the correlations.

Abstract

The correlations of the electrons field-emitted from a superconductor are fully analyzed, both in space and time. It is proposed that a coincidence experiment would reveal a positive correlation between the electrons emitted in opposite directions. The electrons can be entangled and can even violate Bell's inequality. The crucial role played by Andreev's process is scrutinized, analytical formulas are derived for the correlations, and the physics behind the phenomenon is clarified.