Environmental effects on nonlocal correlations

TL;DR

This paper investigates how environmental interactions cause decay of nonlocal quantum correlations, including Bell nonlocality and steering, and establishes bounds for when these resources become non-quantum or classical.

Contribution

It provides a detailed analysis of nonlocality decay under quantum channels and derives bounds on depolarizing parameters affecting steerability in two-qubit states.

Findings

Nonlocality decays to a local hidden state model under environmental effects.

Complete decay of nonlocal resources occurs for certain quantum channels.

Bounds are established for depolarizing maps where steerability is broken.

Abstract

Environmental interactions are ubiquitous in practical instances of any quantum information processing protocol. The interaction results in depletion of various quantum resources and even complete loss in numerous situations. Nonlocality, which is one particular quantum resource marking a significant departure of quantum mechanics from classical mechanics, meets the same fate. In the present work we study the decay in nonlocality to the extent of the output state admitting a local hidden state model. Using some fundamental quantum channels we also demonstrate the complete decay in the resources in the purview of the Bell-CHSH inequality and a 3-settings steering inequality. We also obtain bounds on the parameter of the depolarizing map for which it becomes steerability breaking pertaining to a general class of two qubit states.