## Scientific results on the Theory of QIPC published in international journals and conference proceedings

The partners in RESQ have obtained many important results that have been accepted in the most prestigious journals and conferences in physics and computer science. The number of articles and conference proceedings published in 2003 was 68, of which 12 were in the most highly ranked journals and conference proceedings in the field. The number of articles and conference proceedings published in 2004 was 52, of which 30 were in the most highly ranked journals and conference proceedings in the field. The number of articles and conference proceedings published in 2005-06 was 78, of which 19 were in the most highly ranked journals and conference proceedings in the field.

Some of the most important contributions of RESQ are:

- A large number new proposals for implementation of QIPC in specific physical systems.

- Important new proposals on how to test quantum systems, particularly using non- local correlations, this implied a detailed analysis of the properties of quantum non-locality, often in multidisciplinary collaborations.

- A concerted investigation of the implications of causality, and in particular the "no-signalling" condition, which obtains between two spatially separated observers, for information processing. This has deep implications understanding the origin of the power of QIPC over classical information processing and communication, and results on communication complexity, cryptography, the resources necessary to simulate of quantum systems, have been obtained.

- A much deeper understanding of the resources required in quantum communication, and how these resources can be inter-converted one into the other. For instance investigations in this direction led to a recent article in Nature on state merging.

- Important advances in quantum cryptography, including key distribution, coin tossing and string commitment.

" An exciting class of results are those in which quantum techniques are used to obtain results for classical problems. Some examples are demonstrating the existence of bound classical information, showing how the concept of weak values can be used to study light propagation in optical fibres, the development of Density Matrix Renormalisation Group methods for solving on classical computers problems of quantum statistical mechanics, and several new classical algorithms or proofs of lower bounds for problems in classical computer science.

- Several new results on how quantum communication can help reduce communication complexity

- Several new quantum algorithms, including algorithms for some cases of the hidden subgroup problem, and for finding properties of graphs.

- New quantum direct product theorems, which show that solving n independent cases of a problem simultaneously is not easier than solving the n cases sequentially.

- A detailed investigation of adiabatic quantum computing, including a proof that adiabatic quantum computing is equivalent to standard computing.

In addition to the above one result was deemed sufficiently close to applications for patents to be applied for: partner GAP introduced a patent application for a new protocol for QKD much less sensitive to photon splitting attacks than previous protocols, see quant-ph/0411022.

Some of the most important contributions of RESQ are:

- A large number new proposals for implementation of QIPC in specific physical systems.

- Important new proposals on how to test quantum systems, particularly using non- local correlations, this implied a detailed analysis of the properties of quantum non-locality, often in multidisciplinary collaborations.

- A concerted investigation of the implications of causality, and in particular the "no-signalling" condition, which obtains between two spatially separated observers, for information processing. This has deep implications understanding the origin of the power of QIPC over classical information processing and communication, and results on communication complexity, cryptography, the resources necessary to simulate of quantum systems, have been obtained.

- A much deeper understanding of the resources required in quantum communication, and how these resources can be inter-converted one into the other. For instance investigations in this direction led to a recent article in Nature on state merging.

- Important advances in quantum cryptography, including key distribution, coin tossing and string commitment.

" An exciting class of results are those in which quantum techniques are used to obtain results for classical problems. Some examples are demonstrating the existence of bound classical information, showing how the concept of weak values can be used to study light propagation in optical fibres, the development of Density Matrix Renormalisation Group methods for solving on classical computers problems of quantum statistical mechanics, and several new classical algorithms or proofs of lower bounds for problems in classical computer science.

- Several new results on how quantum communication can help reduce communication complexity

- Several new quantum algorithms, including algorithms for some cases of the hidden subgroup problem, and for finding properties of graphs.

- New quantum direct product theorems, which show that solving n independent cases of a problem simultaneously is not easier than solving the n cases sequentially.

- A detailed investigation of adiabatic quantum computing, including a proof that adiabatic quantum computing is equivalent to standard computing.

In addition to the above one result was deemed sufficiently close to applications for patents to be applied for: partner GAP introduced a patent application for a new protocol for QKD much less sensitive to photon splitting attacks than previous protocols, see quant-ph/0411022.