17 February 2017

Room-temperature single-photon emission demonstrated from defects in GaN films

Demand for faster computers is growing rapidly and the rise of 'big data' demands that novel solutions are explored to deliver quicker results. Weather prediction systems, computation modelling of protein structures and the ever-increasing need for safer communications of confidential data are examples of information that needs to be crunched swiftly. Several platforms are in competition to realise quantum technologies, and among the most promising is one based on a generation of non-classical light sources.

The team of associate professor Igor Aharonovich of Australia's University of Technology Sydney (UTS) School of Mathematical and Physical Sciences (MAPS) and PhD student Amanuel Berhane – in collaboration with professor Dirk Englund and his group at the USA's Massachusetts Institute of Technology (MIT) – have demonstrated that this technology can be realized through commercially available gallium nitride ('Bright Room-Temperature Single-Photon Emission from Defects in Gallium Nitride' Advanced Materials; DOI: 10.1002/adma.201605092).

"Our technologies are based on ultra-bright light pulses that can carry the information at the speed of light, paving the way for quantum cryptography and optical quantum computing," says Aharonovich. "We're developing new solutions for secured communications and quantum information."

Berhane conducted the research that led to this latest discovery of GaN emitters early in 2016. "Evaluating the properties of the new single-photon source in GaN against some of the criteria set for futuristic devices such as brightness and polarization, we concluded the emitters in GaN hold great potential," he says. The UTS team is focused on identifying and rendering semiconductor platforms that would make possible photon-based fast computing. "We work with technologically compatible materials, so the next step to build a quantum processor is becoming more and more viable," Berhane notes.

The team used experimental and numerical modelling to identify a unique arrangement of structural defects in GaN as being the source of emission, says co-author professor Milos Toth of UTS. "Our work demonstrates novel single-photon emission from gallium nitride films, a material that is already a viable platform for LEDs," he adds. "The emission has observed different films having varying thickness and structures."

The team is now focused on integrating these sources with on-chip devices to develop a commercial prototype. Most quantum technologies (such as quantum computers) are still largely in the research stage, with significant strides being made in lab demonstrations. This research demonstrates that use of those technologies is drawing closer, believes the team.

Tags: GaN

Visit: http://onlinelibrary.wiley.com/doi/10.1002/adma.201605092/full

Visit: www.uts.edu.au/staff/igor.aharonovich