22 Mar 2016
Researchers at University of Sydney's Nanoscience Hub say this will help develop more secure communications systems.
With the application of enough computing power, most contemporary security systems can be broken. But a research team at the University of Sydney, Australia, has made what it calls “a major breakthrough” in generating single photons, as carriers of quantum information in security systems, which is expected to raise the cyber security standard.
Results of the collaboration involving physicists at the Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), based in the School of Physics, and electrical engineers from the School of Electrical and Information Engineering, was published in Nature Communications.
The team says its work has resolved a key issue restraining the development of password exchange, which can only be broken by violating the accepted laws of physics. Photons are generated in a pair, and detecting one indicates the existence of the other. This allows scientists to manage the timing of photon events so that they always arrive when they are expected.
Lead author Dr Chunle Xiong from the School of Physics, commented, “Quantum communication and computing are the next-generation technologies poised to change the world. Among a number of quantum systems, optical systems offer particularly easy access to quantum effects. Over the past few decades, many building blocks for optical quantum information processing have developed quickly.
Improving the odds
“Implementing optical quantum technologies has now come down to one fundamental challenge: having indistinguishable single photons on-demand,” he said. “Our 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.”
CUDOS director and co-author of the paper, Professor Benjamin Eggleton said the interdisciplinary research was set to revolutionize secure exchange of data – along with advancing quantum computing, which, for example, can search large databases “exponentially faster”.
“The ability to generate single photons will drive the development of local secure communications systems – for safeguarding defense and intelligence networks, the financial security of corporations and governments and bolstering personal electronic privacy, like shopping online,” Professor Eggleton said. “Our demonstration leverages the CUDOS photonic chip that we have been developing over the last decade, which means this new technology is also compact and can be manufactured with existing infrastructure.”
The Nature Communications article concludes: “This demonstration provides a road map for creating near-deterministic heralded single-photon sources using a resource-efficient and thus scalable multiplexing scheme. With nearly unity efficiency detectors, 90% transmission filters and low-loss switches, this scheme will ultimately provide a solution for photon sources required for optical quantum computing and simulation.”
Co-author and Professor of Computer Systems, Philip Leong, who developed the high-speed electronics crucial for the advance, said he was excited by the prospect of further exploring the marriage of photonics and electronics to develop new architectures for quantum problems: “This advance addresses the fundamental problem of single photon generation – promises to revolutionise research in the area,” he said.
The group – which is now exploring advanced designs and expects real-world applications within three to five years – has 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.
About the Sydney Nanoscience Hub
The following videos explain more about (upper) )the CUDOS group's latest work and (lower) the recently-developed Sydney Nanoscience Hub:
About the Author
Matthew Peach is a contributing editor to optics.org.