Generation of hybrid entanglement between a single-photon polarization qubit and a coherent state

TL;DR

This paper presents a practical scheme for generating hybrid entanglement between a single-photon polarization qubit and a coherent state, using accessible resources and realistic detectors, with adjustable fidelity and success probability.

Contribution

It introduces a novel method combining superposition states, polarization entanglement, and displacement operations to create hybrid entanglement with high fidelity under realistic conditions.

Findings

High fidelity entanglement achievable with low-efficiency detectors.

Adjustable success probability via beam-splitter and displacement parameters.

Feasible with current technology and resource states.

Abstract

We propose a scheme to generate entanglement between a single-photon qubit in the polarization basis and a coherent state of light. The required resources are a superposition of coherent states, a polarization entangled photon pair, beam splitters, the displacement operation, and four photodetectors. Even when realistic detectors with a limited efficiency are used, an arbitrarily high fidelity can be obtained by adjusting a beam-splitter ratio and the displacement amplitude at the price of reducing the success probability. Our analysis shows that high fidelities may be obtained using on-off detectors with low efficiencies and available resource states under current technology.