Entanglement propagation of a quantum optical vortex state

TL;DR

This paper investigates how entanglement in quantum optical vortex states evolves during propagation through coupled waveguides, using Wigner function reconstruction and logarithmic negativity to quantify entanglement changes.

Contribution

It introduces a detailed analysis of entanglement dynamics for vortex states generated by different methods during propagation in waveguides.

Findings

Entanglement persists and evolves during propagation.

Different generation methods affect entanglement dynamics.

Quantitative analysis using logarithmic negativity.

Abstract

We study the entanglement evolution of a quantum optical vortex state propagating through coupled lossless waveguides. We consider states generated by coupling two squeezed modes using a sequence of beam splitters and also by subtracting photons from the signal in spontaneous parametric down conversion. We reconstruct the Wigner function at a later time to study the correlation and quantify the entanglement after propagation using \emph{logarithmic negativity}.