Creating quantum light sources and light source detectors

The University of Adelaide has a world-class quantum materials program which brings together physicists, engineers, material scientists, and key industry partners, including Silanna and DSTG, to identify where quantum materials and solid-state quantum devices can affect impactful change.

Research areas are founded on semiconductor and superconductor quantum materials, including high-power semiconductor lasers, superconducting nanowire single photon detectors, and quantum light sources.

As part of this program, Professor Glenn Solomon and his team are working on developing quantum light sources, and the equipment to detect them, as they have the potential to provide ultimate secure communications, even between Earth-based systems via satellites.

Glenn explains "We have been investigating how light interacts with materials that are engineered to accentuate their quantum properties, and how the resultant devices can be used to create very secure communication channels. We create a quantum dot which contains somewhere between 50,000 and 100,000 atoms that all act like just one atom, but produce much brighter light. We make the quantum dot inside a specially designed crystal where the light builds up as it bounces off different layers in the crystal, further enhancing the brightness of the quantum light."

"We can then use this light to send messages, and due to the quantum nature of the light (a single photon), there is no way to listen in to, or interrupt, this message as the photon would flicker and the sender/receiver would be aware."

"We also need to be able to detect this light, so our team is looking at creating highly efficient superconducting detectors which can be integrated into a robust photonic chip, easily used in real-world conditions. Ideally, we will ultimately have the light source and detector on one chip."

"This type of ultimately secure communication is critical for defence as their current classical methods will reduce in security over the next decade as quantum options become more widely available."

"Our next steps are to increase the efficiency and integration of the light source. We are also looking to deeply understand the physics behind these reactions as this is the key to future improvements in this exciting field of quantum materials."