Dephasing effects on quantum correlations and teleportation in presence of state dependent bath

TL;DR

This paper investigates how a state-dependent environment affects quantum correlations and teleportation fidelity, revealing that initial system-bath correlations can sustain quantum features longer and improve teleportation performance.

Contribution

It provides analytical models for the evolution of entanglement and fidelity in a system with state-dependent bath, highlighting the role of initial correlations in preserving quantum properties.

Findings

Quantum correlations persist longer due to initial system-bath correlations.

Fidelity of quantum teleportation can exceed classical limits with long-time entanglement.

Analytic expressions for entanglement and fidelity evolution are derived.

Abstract

Quantum information protocols are often designed in the ideal situation with no decoherence. However, in real setup, these protocols are subject to the decoherence and thus reducing fidelity of the measurement outcome. In this work, we analyze the effect of state dependent bath on the quantum correlations and the fidelity of a single qubit teleportation. We model our system-bath interaction as qubits interacting with a common bath of bosons, and the state dependence of the bath is generated through a projective measurement on the joint state in thermal equilibrium. The analytic expressions for the time evolution of entanglement, Negativity and average fidelity of quantum teleportation are calculated. It is shown that due to the presence of initial system-bath correlations, the system maintains quantum correlations for long times. Furthermore, due to the presence of finite long time entanglement of the quantum channel, the average fidelity is shown to be higher than its classical value.