Port-based teleportation under pure-dephasing decoherence

TL;DR

This paper investigates how pure-dephasing decoherence impacts port-based quantum teleportation, analyzing noisy scenarios, deriving bounds, and exploring environmental effects through a spin boson model.

Contribution

It provides analytical bounds for teleportation fidelity under decoherence and reveals that noise-adapted measurements can perform worse than ideal ones.

Findings

Analytical lower bounds for entanglement fidelity

Noise-adapted measurements perform worse than noiseless ones

Environmental factors like bath memory and temperature significantly affect fidelity

Abstract

We study deterministic port based teleportation in the presence of noise affecting both the entangled resource state and the measurement process. We focus on a physically motivated model in which each Bell pair constituting the resource interacts with an identical local environment, corresponding to independently distributed entangled links. Two noisy scenarios are analyzed: one with decoherence acting solely on the resource state and ideal measurements, and another with noisy, noise adapted measurements optimised for the given noise model. In the first case, we derive an analytical lower bound and later a closed-form expression for the entanglement fidelity of the teleportation channel and analyze its asymptotic behaviour. In the second, we combine semi analytical and numerical methods. Surprisingly, we find that noise-adapted measurements perform worse than the noiseless ones. To connect the abstract noise description with microscopic physics, we embed the protocol in a spin boson model and investigate the influence of bath memory and temperature on the teleportation fidelity, highlighting qualitative differences between different environments.