Immense Fidelity Enhancement of Encoded Quantum Bell Pairs at Short and
  Long-distance Communication along with Generalized Design of Circuit
Quantum entanglement is a unique criterion of the quantum realm and an
essential tool to secure quantum communication. Ensuring high-fidelity
entanglement has always been a challenging task owing to interaction with the
hostile channel environment created due to quantum noise and decoherence.
Though several methods have been proposed, achieving almost 100% error
correction is still a gigantic task. As one of the main contributions of this
work, a new model for large distance communication has been introduced, which
can correct all bit flip errors or other errors quite extensively if proper
encoding is used. To achieve this purpose, at the very first step, the idea of
differentiating the long and short-distance applications has been introduced.
Short-distance is determined by the maximum range of applying unitary control
gates by the qubit technology. As far as we know, there is no previous work
that distinguishes long and short distance applications. At the beginning, we
have applied stabilizer formalism and Repetition Code for decoding to
distinguish the error correcting ability in long and short distance
communication. Particularly for short distance communication, it has been
demonstrated that a properly encoded bell state can identify all the bit flip,
or phase flip errors with 100% accuracy theoretically. In contrast, if the bell
states are used in long distance communication, the error-detecting and
correcting ability reduces at huge amounts. To increase the fidelity
significantly and correct the errors quite extensively for long-distance
communication, a new model based on classical communication protocol has been
proposed. All the required circuits in these processes have been generalized
during encoding. Proposed analytical results have also been verified with the
Simulation results of IBM QISKIT QASM.
Syed Emad Uddin Shubha Md. Saifur Rahman M. R. C. Mahdy