Entanglement between total intensity and polarization for pairs of coherent states

TL;DR

This paper investigates the entanglement properties between total intensity and polarization in pairs of coherent states, revealing potential for converting proto-entanglement into usable particle entanglement through experimental methods.

Contribution

It introduces a framework for analyzing entanglement between number and polarization or phase in coherent states, using embedding techniques for well-defined variable factorization.

Findings

Entanglement exists between number and polarization in coherent states.

Embedding in larger Hilbert space allows for meaningful factorization of variables.

Proto-entanglement can be converted into real particle entanglement experimentally.

Abstract

We examine entanglement between number and polarization, or between number and relative phase, for pairs of coherent states and two-mode squeezed vacuum via linear entropy and covariance criteria. We consider the embedding of the two-mode Hilbert space in a larger space to get a well-defined factorization of the number-phase variables. This can be regarded as a kind of proto-entanglement that can be extracted and converted into real particle entanglement via feasible experimental procedures. In particular this reveals interesting entanglement properties of pairs of coherent states.