AN international, interdisciplinary team of researchers have made a breakthrough in generating single photons to carry quantum information securely.
The findings are set to revolutionise cybersecurity, along with advancing quantum computing, which can search large databases exponentially faster.
The research work will continue at the Australian Institute for Nanoscale Science and Technology, which launches at the University of Sydney in April 2016.
The collaboration involved physicists at the Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), an ARC Centre of Excellence headquartered in the University of Sydney School of Physics, and electrical engineers from the School of Electrical and Information Engineering.
It also involved research with University of Melbourne, CUDOS nodes at Macquarie University and Australian National University and an international collaboration with Guangdong University of Technology, China.
The team’s work resolved a key issue holding back the development of password exchange, which was being able to generate a single indistinguishable, regular stream of photons on-demand, and at a reasonable rate.
“This research has demonstrated that the odds of being able to generate a single photon can be doubled by using a relatively simple technique – and this technique can be scaled up to ultimately generate single photons with 100% probability,” lead author Dr Chunle Xiong explained.
The results of the breakthrough is a photon switch mechanism, where a photon generator outputs pairs of photons, creating two photon streams. The photon pairs travel at irregular time intervals, but the detection of one photon in a given stream indicates the existence, as well as the timing information of the other.
By using a field programmable gate array and time interval switch alongside the detector, the scientists were able to transform the dual stream of irregular photons into a single stream, where photons travel at programmed, regular intervals, so they always arrive at the time they are expected.
This development is expected to bolster local secure communications systems for safeguarding defence and intelligence networks, corporate and governmental security.
The breakthrough utilises the CUDOS Photonic chip that CUDOS has been developing over the last decade. This means the technology is compact, and can be manufactured into existing infrastructure.