Considerable international research effort has been focussed on experiments in Quantum Computation. The ARC Centre of Excellence in Quantum Computer Technologies (CQCT) is one of the pre-eminent research organisations working in this field. The group is a participant in the CQCT (please see the CQCT website at http://www.qcaustralia.org for more information) and conducts research into photonic quantum computation architectures, one of the two experimental research themes of the Centre.

The vast majority of existing experiments in the field of photonic quantum computation are in free space and make use of polarisation to encode information. This makes the experiments very challenging because they must operate in a light-tight environment and at wavelengths that require complex, bulky and expensive equipment to generate the photons. Such an environment does not lend itself easily to scale-up of photonic encoding systems. Our role within the CQCT is to develop robust and potentially scaleable photonic encoding schemes.

In collaboration with co-workers at the University of Queensland , we have proposed a new scheme for encoding quantum information on photons. This novel photonic encoding scheme - the frequency of the photons - lends itself to operation inside optical fibres. Adoption of this scheme will eliminate the requirement for a light-tight environment for photon quantum computation experiments and may well reduce the reliance on the older approaches to generation of single photons.

ll of the experiments of the Quantum Electronics Group rely on an underlying theoretical framework, which not only motivates the research but also facilitates quantitative analysis. Whilst our primary focus is experiments, we have completed theoretical analyses of a number of potential quantum information experiments. The Quantum Electronics Group is currently conducting experiments that demonstrate the operation of these devices on "bright" beams of light. We have experimental results confirming the operation of one of our inventions. We are currently constructing another experiment to confirm the operation of another. This program of research is funded under the ARC Centres of Excellence Scheme.