Channel nonlocality under decoherence

TL;DR

This paper investigates how quantum channel nonlocality behaves under decoherence, identifying resilient components and demonstrating their importance in quantum protocols and classical simulation advantages.

Contribution

It quantifies nonlocality in bipartite quantum channels under decoherence and reveals components resistant to dephasing noise, highlighting their role in quantum information tasks.

Findings

Resilient nonlocal components persist under dephasing.

Quantum channels can outperform classical simulation in noisy environments.

Classical aspects of channels influence quantum protocol performance.

Abstract

The implementation of realistic quantum devices requires a solid understanding of the nonlocal resources present in quantum channels, and the effects of decoherence on them. Here we quantify nonlocality of bipartite quantum channels and identify its component resisting the effects of dephasing noise. Despite its classical nature, we demonstrate that the latter plays a relevant role in performing quantum protocols, such as state transformations and quantum coding for noisy communication. In the converse direction, we show that simulating certain stochastic processes with quantum channels undergoing decoherence has a communication advantage with respect to their classical simulation.