Controlling nonlocality of bipartite qubit states via quantum channels

TL;DR

This paper investigates how quantum channels derived from X states can control nonlocality in bipartite qubit systems, revealing conditions under which nonlocality can be generated or suppressed.

Contribution

It introduces a characterization of nonlocality generating channels from X states and simplifies nonlocality analysis using minimal parameters.

Findings

Nonlocality generating channels shrink as states move away from maximally mixed.

Nonlocality can be fully characterized with a single parameter in certain cases.

The approach simplifies the analysis of nonlocality in X states.

Abstract

In this paper, we analyze quantum channels derived from a class of two-qubit states known as the X states. In particular, we consider X states that break the Bell's CHSH condition and then characterize the associated inverse Choi-Jamiolkowski maps, which we call nonlocality generating. Interestingly, the region corresponding to nonlocality generating channels shrinks as their stationary state departs from the maximally mixed state. Finally, we demonstrate special cases, where nonlocality can be fully characterized via as little as a single parameter. This approach significantly simplifies the analysis of nonlocality for the X states.