Analyzing performance of $f$-deformed displaced Fock state in continuous-variable quantum teleportation

TL;DR

This paper investigates the performance of $f$-deformed displaced Fock states in continuous-variable quantum teleportation, demonstrating enhanced fidelity and identifying optimal regimes for experimental realization.

Contribution

It derives analytical expressions for non-Gaussian entangled states using $f$-deformed operators and analyzes their teleportation fidelity and entanglement properties.

Findings

Nonlinear $f$-deformation enhances teleportation fidelity beyond the threshold.

Photon-subtracted displaced Fock states show maximum efficiency as quantum channels.

Entangled photon-added states have higher entanglement; photon-subtracted states have stronger EPR correlations.

Abstract

Performing non-Gaussian operations, namely photon addition, photon subtraction, photon-addition-then-subtraction, photon-subtraction-then-addition can successfully enhance the fidelity of the continuous-variable quantum teleportation. However, a shortcoming of these non-Gaussian resources is that they are probabilistic in nature. In this article, we investigate the success probability of the non-Gaussian resources for optimal performance of the ideal teleportation protocol. To this end, we first derive the analytical expression for the two-mode entangled channel having $f$-deformed displaced Fock state or photon-added displaced Fock state or photon-subtracted displaced Fock state at one port and vacuum at another port of a symmetric beam-splitter. The generalized displaced Fock states are obtained by replacing the conventional bosonic functions by the nonlinear $f$-deformed operators such as $A=af(a^\dagger a)$ and $B=af(a^\dagger a)^{-1}$. The Wigner characteristic functions describing these three aforementioned non-Gaussian states are determined and utilized to attain the teleportation fidelity for input coherent and squeezed vacuum states. It is found that the nonlinear substitution leads to an enhancement in teleportation fidelity beyond the threshold limit. Moreover, the entangled photon-subtracted displaced Fock state demonstrates maximum efficiency as a quantum channel for teleporting single-mode coherent and squeezed states. We provide the squeezing regime values corresponding to the optimal performance of the non-Gaussian states considered, which will be of significant interest to the experimental fraternity. Further, we show that the entangled photon-added displaced Fock states have larger amount of entanglement but the entangled photon-subtracted displaced Fock states have stronger Einstein-Podolsky-Rosen correlation.