English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Tomography of the two qubit density matrix shared by Alice and Bob is anessential ingredient for guaranteeing an acceptable margin of confidentialityduring the establishment of a secure fresh key through the Quantum KeyDistribution (QKD) scheme. We show how the Singapore protocol for keydistribution is optimal from this point of view, due to the fact that it isbased on so called SIC POVM qubit tomography which allows the most accuratefull tomographic reconstruction of an unknown density matrix on the basis of arestricted set of experimental data. We illustrate with the help ofexperimental data the deep connections that exist between SIC POVM tomographyand discrete Wigner representations. We also emphasise the special role playedby Bell states in this approach and propose a new protocol for Quantum KeyDistribution during which a third party is able to concede or to deny APOSTERIORI to the authorized users the ability to build a fresh cryptographickey.

Wigner tomography of two qubit states and quantum cryptography