Probing Quantitatively Two-electron Entanglement with a Spintronic Quantum Eraser

TL;DR

This paper proposes a spintronic quantum eraser device that directly links measurable current correlations to the degree of two-electron entanglement, enabling experimental quantification of entanglement states.

Contribution

It introduces a novel method to measure two-electron entanglement using Aharonov-Bohm oscillations in a spintronic setup, connecting measurable signals to entanglement concurrence.

Findings

Concurrence is proportional to Fano factor oscillation amplitude.

Singlet and triplet states are distinguished by Fano factor signs.

The setup uses existing electronic Mach-Zehnder interferometers and spin filters.

Abstract

We design an ingenious spintronic quantum eraser to quantitatively probe the two-electron entanglement. It is shown that the concurrence of two spin-entangled electrons is directly given by the Aharonov-Bohm oscillation amplitude of the Fano factor, a measurable current-current correlation, making it rather promising to experimentally quantify the two-electron entanglement. The singlet and triplet entangled states are distinguished by the opposite signs in the Fano factor. Since the main building blocks in the designed setup, an electronic Mach-Zehnder interferometer and a spin filter, have already been implemented, our proposal is particularly pertinent to experiments.