In this paper we study the nonlocal properties of two-qubit Werner states parametrized by the visibility parameter 0≤p≤1. A family of Bell inequalities is constructed that proves the two-qubit Werner states to be nonlocal for the parameter range 0.7056<p≤1. This is slightly wider than the range 0.7071<p≤1, corresponding to the violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality. This answers a question posed by Gisin in the positive, i.e., there exist Bell inequalities which are more efficient than the CHSH inequality in the sense that they are violated by a wider range of two-qubit Werner states.
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - Sep 17 2008|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics