The application of quantum mechanics to information related fields such as
communication, computation and cryptography is a fast growing line
of research that has been witnessing an outburst of theoretical and experimental
results, with possible practical applications.
On the one hand, quantum cryptography with its impact on secrecy of transmission
is having its first important actual implementations; on the other hand, the
recent advances in quantum optics, ion trapping, BEC manipulation,
spin and quantum dot technologies allow us to put to direct test a great deal of
theoretical ideas and results.
These achievements have stimulated a reborn interest in various
aspects of quantum mechanics, creating a unique interplay between
physics, both theoretical and experimental, mathematics,
information theory and computer science.
In view of all these developments, it appeared timely to organize a meeting
where graduate students and young researchers could be exposed to the
fundamentals of the theory, while senior experts could exchange their
latest results.
The activity was structured as a school followed
by a workshop, and took place at The Abdus Salam International
Center for Theoretical Physics (ICTP) and The International School for Advanced
Studies (SISSA) in Trieste, Italy, from 12–23 June 2006.
The meeting was part of the activity of the Joint European Master Curriculum
Development Programme in Quantum Information, Communication, Cryptography and
Computation, involving the Universities of Cergy–Pontoise (France),
Chania (Greece), Leuven (Belgium), Rennes1 (France) and Trieste (Italy).
This special issue of Journal of Physics A: Mathematical and Theoretical collects
22 contributions from well known experts who took part in the workshop.
They summarize the present day status of the research in the manifold
aspects of quantum information.
The issue is opened by two review articles, the first by G Adesso and
F Illuminati discussing entanglement in continuous variable systems, the second
by T Prosen, discussing chaos and complexity in quantum systems. Both
topics have theoretical as well as experimental relevance and are
likely to witness a fast growing development in the near future.
The remaining contributions present more specific and very recent results.
They involve the study of the structure of quantum states and their estimation
(B Baumgartner et al, C King et al, S Olivares et al, D Petz et al and W van Dam et al),
of entanglement generation and its quantification
(G Brida et al, F Ciccarello et al, G Costantini et al,
O Romero-Isart et al, D Rossini et al, A Serafini et al and D Vitali et al),
of randomness related effects on entanglement behaviour
(I Akhalwaya et al, O Dahlsten et al and L Viola et al),
and of abstract and applied aspects of quantum computation and communication
(K Audenart, G M D'Ariano et al, N Datta et al, L C Kwek et al and M Nathanson et al).
We would like to express our gratitude to the European Commission, the
Abdus Salam ICTP, SISSA and Eurotech SpA (Amaro, Udine, Italy)
for financial and/or logistic support. Special thanks also go to the
workshop secretary Marina De Comelli, and the secretaries of the
Department of Theoretical Physics, University of Trieste, Sabrina
Gaspardis and Rosita Glavina for their precious help and assistance.