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Enabling Technologies for Quantum Information Systems


Despite recent advances in quantum information research there has been a lack of progress in developing the technologies that will be required for practical applications of these new concepts. EQUIS seeks to address this problem by demonstrating research prototypes of a range of key enabling technologies for quantum communication systems. These include single photon detectors, integrated interferometers and customized photon data acquisition PC cards. The project aims to use these new technologies to demonstrate PC-based quantum key distribution systems with enhanced performance in terms of bit-rate and distance and much improved practicality. These aims will be achieved by bringing together, in a single project, a range of key specialist technological and system skills and focussing them on the specific objective of the development of practical, manufacturable, enabling technologies for quantum communications systems.

EQUIS aims to develop a number of vital enabling technologies for photon-based quantum processing and communication systems and to evaluate their performance within a quantum cryptography testbed. By developing components that are compatible with the optical fibre infrastructure and suitable for integration into personal computers, EQUIS seeks to expand the performance of quantum key distribution to longer distances and higher bit rates and also to generally enhance the practicality of the technique. The project will help to establish the credibility of quantum communication systems and to stimulate and steer commercial developments of the component and sub-system technologies that will be required for future commercial exploitation. To enhance the probability of achieving this goal, the project is strongly focussed on new technologies that combine enhanced performance with a realistic prospect for low cost manufacture.

Project EQUIS is organised into seven Work Packages that represent the main themes of the planned work. Three Work Packages deal with the vitally important issue of the design, fabrication and testing of new types of single-photon detector and associated circuitry that are specifically designed for applications in fibre-based quantum communication systems.
Two types of detector will be investigated:
(1) InGaAs/InP avalanche photodiodes (APDs) intended for applications over multi-kilometre distances within the fibre low loss window at a wavelength of 1.55 micron and
(2) shallow-junction Si APDs optimised for high speeds and intended for high bit rate applications over the shorter distances (up to 10 km) that would be appropriate for local area networks LANs). Two other Work Packages deal with integration issues. One is concerned with sub-system integration of the required single photon counting data acquisition hardware into a PC, and the second deals with integration at the optical device level by developing waveguide-based versions of the interferometer that provides the basic quantum channel in a QC system. A sixth Work Package will develop an application of the new long-wavelength single photon detectors in time-resolved photoluminescence spectrosopy of narrow band gap, solution grown, of HgTe and Hg/Cd Te quantum dots. This is aimed at supporting the development of a new class of materials that may have future applications as basic quantum processing elements that operate at fibre compatible wavlengths. The final Work Package will develop the main testbed that will be used to trial the new component technologies developed under the other Work Parts. The testbed will take the form of a PC-based, 1.55 micron wavelength, quantum cryptography (QC)system that will be used to demonstrate secure PC-PC interconnection over fibre installed in the UK national network.

Funding Scheme

CSC - Cost-sharing contracts


EH14 4AS Edinburgh
United Kingdom

Participants (4)

Piazzale Aldo Moro 7
00185 Roma
United Kingdom
Wear Glass Works
SR4 6EJ Sunderland
Rudower Chaussee 29
12489 Berlin
Piazza Leonardo Da Vinci 32
20133 Milano