Experimental four-qubit bound entanglement
2009 (English)In: Nature Physics, ISSN 1745-2473, E-ISSN 1745-2481, Vol. 5, no 10, 748-752 p.Article in journal (Refereed) Published
Entanglement is one of the most puzzling features of quantum theory and of great importance for the new field of quantum information. Being a peculiar form of entanglement, bound entanglement emerges in certain mixed quantum states. This form of entanglement is not distillable by local operators and classical communication. Bound-entangled states are different from both the free entangled (distillable) and separable states. Here we report on the first experimental demonstration of a four-qubit polarization bound-entangled state, the so-called Smolin state. We have fully characterized its entanglement properties. Moreover, we have realized unlocking of the entanglement protocol for this state. The special properties of the Smolin state constitute a useful quantum resource for new multiparty communication schemes.
Place, publisher, year, edition, pages
2009. Vol. 5, no 10, 748-752 p.
mixed states, separability criterion, density-matrices, quantum
IdentifiersURN: urn:nbn:se:su:diva-59659DOI: 10.1038/NPHYS1372ISI: 000271185400016OAI: oai:DiVA.org:su-59659DiVA: diva2:432149
authorCount :22011-08-012011-07-052011-12-20Bibliographically approved