Feasible and economical scheme to entangle a polarized coherent state and a polarized photon

Abstract

We design a scheme to generate a new type of hybrid entanglement between a macroscopic polarized coherent state and a single polarized photon. Concretely, a polarized Schrodinger cat state, an entangled polarized photon pair, and a polarized coherent state, which have been prepared off-line, are supplied as inputs to our scheme. Then, using conventional optical devices such as beam splitters, polarizing beam splitters, half-wave plates, and photon-number-resolving detectors, all the necessary operations can be effectively performed in-line. Conditioned on photon detection results, creation of the desired hybrid entanglement is heralded. The total success probability of our scheme is twice as high as that in existing schemes for unpolarized coherent states. Our scheme is not only feasible but also economical with regard to resource consumption because no active displacement operations must be utilized in-line. We also consider practical factors affecting the scheme performance, including decoherence of the input states, realistic resources, and device imperfections. Detailed analyses show that our scheme is robust against small imperfection effects and could be implemented with current technology. The proposed hybrid entanglement would serve as a vital resource for processing information encoded in superpositions of differently polarized coherent states which represent a new format of qubit.