Experimentally observed decay of higher-dimensional entanglement through turbulence

TL;DR

This study investigates how atmospheric turbulence affects high-dimensional entangled photonic states, combining theoretical modeling and experimental validation to understand entanglement decay in turbulent conditions.

Contribution

It provides the first combined theoretical and experimental analysis of high-dimensional entanglement decay through atmospheric turbulence using a single phase screen model.

Findings

Entanglement decreases with increasing turbulence strength.

Good agreement between theoretical predictions and experimental results.

High-dimensional entanglement shows resilience up to certain turbulence levels.

Abstract

The evolution of high dimensional entanglement in atmospheric turbulence is investigated. We study the effects of turbulence on photonic states generated by spontaneous parametric down-conversion, both theoretically and experimentally. One of the photons propagates through turbulence, while the other is left undisturbed. The atmospheric turbulence is simulated by a single phase screen based on the Kolmogorov theory of turbulence. The output after turbulence is projected into a three-dimensional (qutrit) basis composed of specific Laguerre-Gaussian modes. A full state tomography is performed to determine the density matrix for each output quantum state. These density matrices are used to determine the amount of entanglement, quantified in terms of the negativity, as a function of the scintillation strength. Theoretically, the entanglement is calculated using a single phase screen approximation. We obtain good agreement between theory and experiment.