Quantum computing speeds up, one photon at a time
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A team has created a device which can only deliver very little, but also gives out a lot.
A team of engineers and researchers have made a significant breakthrough in photonics, with an optical chip that can deliver a single photon at a time. The applications are immense, helping the development of complex quantum technologies, completely secure communications, quantum measurement, the simulation of biological and chemical systems and the big thriller - quantum computing.
A collaborative effort from many at the Australian Research Council Centre of Excellence for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS) led to the development. Research in the latest phase was carried out at the University of Sydney's School of Physics and has been published in Nature Communications.
Earlier efforts by different groups have shown that photons can be used to carry quantum information. With a chip that can produce just one photon at a time, designers could be able to control the flow enough to create large-scale working prototypes.
“It is easy for us to generate photons at high rates, but it's much harder to ensure they come out one by one because photons are gregarious by nature and love to bunch together,” said Matthew Collins, a PhD student from CUDOS at the University of Sydney.
“For that reason the quantum science community has been waiting over a decade for a compact optical chip that delivers exactly one photon at a time at very high rates.”
Several breakthroughs were made just for the tiny new device to become possible, CUDOS researchers say.
“A key breakthrough for this research was the CUDOS development of photonic chips that slow light,” said Professor Ben Eggleton, co-author of the research paper.
“This makes single photon generation more likely, reducing energy demands and allowing extremely compact devices with lengths no longer than 200 microns, the width of a human hair.”
“The smaller these systems are, the more we can fit onto a chip, and the more we can fit onto a chip the more likely we are to guarantee a single photon when we want it,” said co-author Associate Professor Michael Steel.
The team will now move to the next phase of research; integrating all the components so far into a single ‘push-button’ photo-emitting chip, it can then be deployed in future photonic quantum technologies.