pdf files of
Programme Booklet >>
and
Abstracts of all Talks >>

You will receive a hard copy of these files at the registration desk.

Sponsors

Pauli Center for Theoretical Studies

The Swiss National Science Foundation

ETH Zurich (Computer Science and Physics Department)

Quantum Science and Technology

CQT Singapore

QAP European Project

Sandia National Laboratories

Institute for Quantum Computing

id Quantique

Highly entangled states with almost no secrecy

Andreas Winter, NUS Singapore and Bristol

joint work with Matthias Christandl and Norbert Schuch

We illuminate the relation between entanglement and secrecy by providing the first example of a quantum state that is highly entangled, but from which, nevertheless, almost no secrecy can be extracted. More precisely, we provide two bounds on the bipartite entanglement of the totally antisymmetric state in dimension d x d. First, we show that the amount of secrecy that can be extracted from the state is low, to be precise it is bounded by O(1/d). Second, we show that the state is highly entangled in the sense that we need a large amount of singlets to create the state: entanglement cost is larger than a constant, independent of d. Our findings also clarify the relation between the squashed entanglement and the relative entropy of entanglement.