Controlled quantum teleportation between discrete and continuous physical systems

TL;DR

This paper demonstrates a scheme for controlled quantum teleportation between discrete and continuous quantum systems using hybrid entangled states, achieving high fidelity depending on phase differences, with practical linear optical implementation.

Contribution

It introduces a novel hybrid entangled state for controlled teleportation between discrete and continuous variables, with experimental feasibility using standard optical components.

Findings

Teleportation fidelity depends on phase difference, approaching perfection near 0 or π.

High-fidelity teleportation is achievable independently of amplitude and squeezing parameters.

The scheme is practically implementable with linear optical components.

Abstract

Quantum teleportation of an unknown state basing on the interaction between discrete-valued states (DV) and continuous-valued states (CV) presented a particular challenge in quantum technologies. Here we consider the problem of controlled quantum teleportation of an amplitude-matched CV qubit, encoded by a coherent state of a varied phase as a superposition of the vacuum- and single-photon optical states among two distant partners Alice and Bob, with the consent of controller, Charlie. To achieve this task, we use an hybrid tripartite entangled state (interaction between the discrete and continuous variables states) as the quantum resource where the coherent part belongs to Alice, while the single-photon belongs to Bob and Charlie and the CV qubit is at the disposal of Alice. The discrete-continuous interaction is realized on highly transmissive beam-splitter. We have shown that the perfectly of teleportation fidelity depends on the phase difference between the phase of the state to teleport and the phase of the sender's mode, we found that for a difference which approaches 0 or $\pi$, near perfect controlled quantum teleportation can be obtained in terms of the fidelity and independently of the amplitude $\alpha$ and the squeezing parameter $\zeta$. Experimentally, this proposed scheme has been implemented using linear optical components such as beam splitter, phase shifters and photon counters.