Abstract
We find two two-qubit bipartite states such that arbitrarily many copies of one or the other cannot exhibit nonlocal correlations in a two-setting–two-outcome Bell scenario. However, the bipartite state violates the Clauser-Horne-Shimony-Holt (CHSH) Bell inequality [J. F. Clauser, M. A. Horne, A. Shimony, and R. A. Holt, Phys. Rev. Lett. 23, 880 (1969).] by an amount of 2.023. We also identify a CHSH-local state such that is CHSH inequality-violating. The tools employed can be easily adapted to find instances of nonlocality activation in arbitrary Bell scenarios.
- Received 22 November 2010
DOI:https://doi.org/10.1103/PhysRevLett.106.060403
© 2011 American Physical Society