Generation of Nonlocality

TL;DR

This paper proposes a protocol to restore Bell nonlocality in two-qubit states affected by environmental interactions, even when unitary operations fail, enhancing quantum resource management.

Contribution

It introduces a novel prescription to recover nonlocality from local states, including those with a local hidden variable model, under environmental influences.

Findings

The protocol successfully transforms local states into nonlocal states.

It retrieves nonlocality from states with a local hidden variable model.

The method outperforms unitary actions in generating nonlocality.

Abstract

Environmental influences are typical in any practical situation which in turn can have fatal effects on quantum resources. Bell nonlocality is such an important resource. Some environmental interactions can lead to nonlocality being lost. In such situations, it is vital to find possible prescriptions to retrieve nonlocality. The present work lays down one such prescription. Precisely, we have studied some well-known classes of states under the ambit of the Bell-CHSH inequality in two qubits, where we start from a Bell-CHSH local state and can transform it into a nonlocal state through our protocol. The efficacy of the protocol is further established from the fact that it can retrieve nonlocality from states admitting a LHV(local hidden variable) model. The strength of the prescription is validated by the fact that it can generate nonlocality from states when even unitary action on the composite system fails.