Tomographic quantum cryptography: equivalence of quantum and classical key distillation.
Phys Rev Lett 91:9 (2003) 097901
Abstract:
The security of a cryptographic key that is generated by communication through a noisy quantum channel relies on the ability to distill a shorter secure key sequence from a longer insecure one. For an important class of protocols, which exploit tomographically complete measurements on entangled pairs of any dimension, we show that the noise threshold for classical advantage distillation is identical with the threshold for quantum entanglement distillation. As a consequence, the two distillation procedures are equivalent: neither offers a security advantage over the other.DIRECT DETECTION OF QUANTUM ENTANGLEMENT
World Scientific Publishing (2003) 621-630
An experimental observation of geometric phases for mixed states using NMR interferometry
(2003)
Direct estimation of functionals of density operators by local operations and classical communication
ArXiv quant-ph/0304123 (2003)
Abstract:
We present a method of determining important properties of a shared bipartite quantum state, within the ``distant labs'' paradigm, using \emph{only} local operations and classical communication (LOCC). We apply this procedure to spectrum estimation of shared states, and locally implementable structural physical approximations to incompletely positive maps. This procedure can also be applied to the estimation of channel capacity and measures of entanglement.Direct estimation of functionals of density operators by local operations and classical communication
(2003)