Achieving near-unity fidelity in conventional continuous-variable quantum teleportation schemes based on two-mode squeezed vacuum states is fundamentally unattainable. To overcome this limitation, alternative approaches utilizing ensembles of two-dimensional entangled qubits have been proposed. In this work, we investigate continuous-variable quantum teleportation employing entangled qutrit resources under realistic noise effects. The results demonstrate that the proposed scheme performs well in both ideal and noisy conditions, enabling high-fidelity teleportation with a reasonable success probability.
The need for high-fidelity quantum teleportation arises in a variety of quantum algorithms and protocols. Unfortunately, conventional continuous-variable teleportation schemes rely on Einstein–Podolsky–Rosen states that yield a fidelity that approaches unity only in the limit of an unphysical amount of squeezing. A new method that utilizes an ensemble of single photon entangled states, qubits, to teleport continuous variable (CV) states with fidelity approaching unity with finite resources was recently proposed by Andersen and Ralph [Phys. Rev. Lett.111, 050504 (2013)]. We extend these ideas to consider the general case of using maximally entangled d-level states, qudits, to teleport a CV state and discuss how the corresponding results are affected. In particular, we find that, by using qudits with dimension greater than two, we can achieve a higher fidelity with comparable resources.
In this work, we investigate the performance of non-Gaussian entangled resources in continuous-variable quantum teleportation within a realistic setting. We describe the characteristic functions of three distinct entangled resources, a two-mode squeezed vacuum state, a two-mode photon-subtracted squeezed state, and a two-mode photon-added squeezed state. We extend the theoretical analysis by Yang et al. to include the realistic experimental conditions such as photon losses, imperfect measurements which typically affect continuous-variable quantum teleportation. Our results demonstrate that even in non-ideal situations, the photon-subtracted squeezed state outperforms the other two resources in the low squeezing regime, keeping fidelity above the classical threshold that suggests the robustness of photon-subtracted squeezed state in practical teleportation applications. We further analyze the EPR correlations of these entangled resources, revealing that the photon-subtracted squeezed state exhibits stronger EPR correlations than the original two-mode squeezed vacuum state and the two-mode photon-added squeezed state. This study merges theoretical models with realistic imperfections and utilizes non-Gaussian entanglement into high-fidelity quantum teleportation.
Glauber's coherent state is denoted by
∣α⟩ and its two-mode extension is represented by
∣α,β⟩. In this work, we introduce a two-mode superposition operator
A=tab+ra†b†, whose action on the two-mode coherent state produces the two-mode coherent superposed quantum state
∣ψ⟩=(tab+ra†b†)∣α,β⟩. We investigate the nonclassicality and quantum non-Gaussianity of this state by means of the Wigner distribution and Wigner logarithmic negativity. Once its intrinsic nonclassical and non-Gaussian structure is established, the state is employed as the entangled resource in the Braunstein-Kimble continuous-variable (CV) teleportation protocol. We compute the ideal teleportation fidelity for coherent and squeezed inputs and analyze how the strengths of nonclassicality and non-Gaussianity influence the teleportation efficiency. Our results identify specific parameter regimes where enhanced non-Gaussian features or increased nonclassicality enable fidelities beyond the classical threshold, thereby revealing the operational significance of engineered two-mode quantum states in CV quantum information processing.