Bidirectional Teleportation using Fisher Information

TL;DR

This paper reformulates a bidirectional quantum teleportation protocol using Bloch vectors and Pauli operators, analyzing how initial state settings influence fidelity and Fisher information, and demonstrating the advantages of multi-parameter estimation.

Contribution

It introduces a new analytical and numerical approach to evaluate bidirectional teleportation using Fisher information and Bloch vectors, highlighting the impact of initial state polarization.

Findings

Maximum fidelity and Fisher information occur when qubits and triggers are similarly polarized.

Minimum values are observed when initial qubits have different polarization or non-zero phase.

Multi-parameter estimation outperforms single-parameter, satisfying classical and quantum bounds.

Abstract

In this contribution, we reformulated the bidirectional teleportation protocol suggested in [7], by means of Bloch vectors as well as the local operations are represented by using Pauli operators. Analytical and numerical calculations for the teleported state and Fisher information are introduced. It is shown that both quantities depend on the initial state settings of the teleported qubits and their triggers. The Fidelities and the Fisher information of the bidirectionally teleported states are maximized when the qubit and its trigger are polarized in the same direction. The minimum values are predicted if both initial qubits have different polarization or non-zero phase. The maximum values of the Fidelity and the quantum Fisher information are the same, but they are predicted at different polarization angles. We display that the multi-parameter form is much better than the single parameter form, where it satisfies the bounds of classical, entangled systems and the uncertainty principle.