Bound entanglement maximally violating Bell inequalities: Quantum entanglement is not fully equivalent to cryptographic security
- Faculty of Applied Physics and Mathematics, Gdansk University of Technology, Gdansk (Poland)
It is shown that Smolin four-qubit bound entangled states [J. A. Smolin, Phys. Rev. A 63, 032306 (2001)] can maximally violate the simple two-setting Bell inequality similar to the standard Clauser-Horne-Shimony-Holt (CHSH) inequality. The simplicity of the setting and the robustness of the entanglement make it promising for current experimental technology. On the other hand, the entanglement does not allow for secure key distillation, so neither entanglement nor maximal violation of Bell inequalities implies directly the presence of a quantum secure key. As a result, one concludes that two tasks--reducing of communication complexity and cryptography--are not (even qualitatively) equivalent in a quantum multipartite scenario.
- OSTI ID:
- 20852858
- Journal Information:
- Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 74; ISSN 1050-2947; ISSN PLRAAN
- Country of Publication:
- United States
- Language:
- English
Similar Records
Experimental Bell-inequality violation without the postselection loophole
Strong violations of Bell-type inequalities for path-entangled number states