Entanglement in a Noninteracting Mesoscopic Structure

TL;DR

This paper investigates how entanglement arises in a mesoscopic device splitting free fermions, analyzing Bell inequality violations and their dependence on device parameters, with implications for quantum information processing.

Contribution

It provides a detailed analysis of entanglement generation and Bell inequality violation in a noninteracting mesoscopic structure, highlighting the role of local correlations and post-selection.

Findings

Bell inequality violation depends on tunneling parameters

Local spin-singlet correlations are key to entanglement

Time window for Bell violation varies with device transparency

Abstract

We study the time dependent electron-electron and electron-hole correlations in a mesoscopic device which is splitting an incident current of free fermions into two spatially separated particle streams. We analyze the appearance of entanglement as manifested in a Bell inequality test and discuss its origin in terms of local spin-singlet correlations already present in the initial channel and the action of post-selection during the Bell type measurement. The time window over which the Bell inequality is violated is determined in the tunneling limit and for the general situation with arbitrary transparencies. We compare our results with alternative Bell inequality tests based on coincidence probabilities.