Entanglement transfer through the turbulent atmosphere

TL;DR

This paper investigates how polarization-entangled light states behave when transmitted through turbulent atmospheric channels, revealing that under certain conditions, entanglement can be preserved better than in standard loss scenarios.

Contribution

It provides analytical insights into entanglement transfer through turbulent atmosphere, highlighting the role of background radiation and dark counts in preserving entanglement.

Findings

Fluctuating loss channels can maintain entanglement better than standard channels with postselection.

Violations of Bell inequalities are possible after atmospheric transmission.

Background radiation and dark counts influence entanglement preservation.

Abstract

The propagation of polarization-entangled states of light through fluctuating loss channels in the turbulent atmosphere is studied, including the situation of strong losses. We consider violations of Bell inequalities by light, emitted by a parametric down-conversion source, after transmission through the turbulent atmosphere. It is shown by analytical calculations, that in the presence of background radiation and dark counts, fluctuating loss channels may preserve entanglement properties of light even better than standard loss channels, when postselected measurements are applied.