Efficiency of photonic state tomography affected by fiber attenuation

TL;DR

This paper analyzes how fiber attenuation impacts the accuracy of photonic state tomography, especially for entangled qubits and qutrits, by modeling photon loss and its effect on entanglement detection over distance.

Contribution

It introduces a formalism for photon loss in quantum state tomography using open quantum systems theory and models the impact of fiber length on tomography quality and entanglement detection.

Findings

Tomography quality decreases with fiber length due to photon loss.

Entanglement detection becomes less reliable over longer fibers.

Theoretical modeling aligns with numerical simulations of photon loss.

Abstract

In this article, we investigate the efficiency of photonic state tomography in the presence of fiber attenuation. The theoretical formalism of the photon loss is provided by implementing methods from the theory of open quantum systems. The quantum state is reconstructed from photon counts obtained for symmetric informationally complete POVMs. The number of photons that reach the detectors is numerically modeled by the binomial distribution, which describes the loss of light caused by the medium. This approach allows us to study the quality of state tomography versus the length of the fiber. In particular, we focus on entangled qubits and qutrits, which are sent through fibers of different lengths. The amount of entanglement detected by the measurement scheme is quantified and presented on graphs. The results demonstrate how the quality of photonic tomography depends on the distance between the source and the receiver.