The project concentrates on a new and actively developing field of modern information technology: quantum information, that includes as inherent parts quantum cryptography and quantum computers. The project will contribute to the theoretical and experimental development of both parts. In the field of quantum cryptography the project objectives are the following. To investigate modern schemes of quantum cryptography for long-distance communication lines with realistic losses. In particular, to determine the maximal information which can leak to eavesdropper for a given loss (bit error rate) in quantum cryptographic channels.
To investigate, in parallel, both theoretically and experimentally three specific quantum cryptography protocols:
the traditional protocol based on a single photon source;
a protocol based on a bright source of entangled phase-locked states of light;
and the so-called relativistic protocol.
The second part of the project is concentrated on one of the well-known foreseen applications of quantum computers where they will be much more powerful compared to the classical ones - the simulation of physical quantum systems.
The objective of this part of the project is to develop numerical methods for simulating quantum information processing in many-body systems with subsequent application
(i) to the creation of an universal numerical simulator of quantum systems with 5-10 identical particles that can be used in particular, for the modeling of a real quantum processor with 10 qubits, and to finding an optimal scheme of quantum solid-state processor on 5-10 qubits with special accounting for quantum operations reconstruction;
(ii) to modeling of entanglement distribution along a two-dimensional lattice of qubits subjected to non-holonom control and Zeno-type measurements;
(iii) to the investigation of entanglement role in phase transition phenomena in many-body systems.
The results of the project will have fundamental significance, extending our knowledge in novel areas of information technologies like quantum cryptography and quantum computers. Some principal new theoretical and experimental results, as well as important recommendations for practice, may be expected. In particular, the schemes of quantum cryptography to be developed and implemented as well as single photon sources to be created will have obvious applications in the state organizations as well as in private companies to ensure the security of significant information exchange. The universal simulator for 5-10 qubit systems and results on entanglement distribution along the two-dimensional lattice of qubits will be of great importance for creating a scalable quantum computer and for other new technologies.