Entanglement and classical nonseparability convertible from orthogonal polarizations

TL;DR

This paper introduces a method to convert polarization-based nonclassicality into entanglement and classical nonseparability in optical states, with potential applications in quantum information processing.

Contribution

It proposes a novel approach to generate and characterize entanglement and nonseparability from polarization superpositions using nonclassicality in coherent and displaced Fock states.

Findings

Equivalent Bell states can be generated from superpositions.

The ratio of entanglement to nonseparability depends on displacement amplitudes.

Experimental methods for state generation and measurement are proposed.

Abstract

The nonclassicality of a macroscopic single-mode optical superposition state is potentially convertible into entanglement, when the state is mixed with the vacuum on a beam splitter. Considering light beams with polarization degree of freedom in Euclidean space as coherent product states in a bipartite Hilbert space, we propose a method to convert the two orthogonal polarizations into simultaneous entanglement and classical nonseparability through nonclassicality in the superpositions of coherent and displaced Fock states. Equivalent Bell state emerges from the resulted superpositions and the proportion of mixed entanglement and nonseparablity is determined by the displacement amplitudes along the polarization directions. We characterize the state nonclassicality via features in Wigner distributions and propose an experimental method for generating these states and measuring them via homodyne tomography.