Robust entangled qutrit states in atmospheric turbulence

TL;DR

This paper investigates the robustness of entangled qutrit states propagating through atmospheric turbulence, identifying states that maintain entanglement longer than maximally entangled ones using an infinitesimal-propagation model.

Contribution

It introduces optimized initial qutrit states that are more resistant to entanglement decay in turbulence compared to standard maximally entangled states.

Findings

Optimized qutrit states retain entanglement longer.

Maximally entangled states are less robust in turbulence.

The infinitesimal-propagation equation models entanglement decay.

Abstract

The entangled quantum state of a photon pair propagating through atmospheric turbulence suffers decay of entanglement due to the scintillation it experiences. Here we investigate the robustness against this decay for different qutrit states. We use an infinitesimal-propagation equation to obtain the density matrix as a function of the propagation distance and we use the tangle to quantify the entanglement between a pair of qutrits. The evolution of various initial states as they propagate through turbulence is considered. Using optimization of the initial parameters, we obtain expressions for bipartite qutrit states that retain their initial entanglement longer than the initially maximally entangled states.