Centre updates

New photonic chip promises more robust quantum computers

Scientists have developed a topological photonic chip to process quantum information, promising a more robust option for scalable quantum computers.

The research team, led by RMIT University’s Dr Alberto Peruzzo, has for the first time demonstrated that quantum information can be encoded, processed and transferred at a distance with topological circuits on the chip. The research is published in Science Advances.

The breakthrough could lead to the development of new materials, new generation computers and deeper understandings of fundamental science.

In collaboration with scientists from the Politecnico di Milano and ETH Zürich, the researchers used topological photonics – a rapidly growing field that aims to study the physics of topological phases of matter in a novel optical context – to fabricate a chip with a ‘beamsplitter’ creating a high precision photonic quantum gate.

“We anticipate that the new chip design will open the way to studying quantum effects in topological materials and to a new area of topologically robust quantum processing in integrated photonics technology,” says Peruzzo, Chief Investigator at the ARC Centre of Excellence for Quantum Computation and Communication Technology (CQC2T) and Director, Quantum Photonics Laboratory, RMIT.

“Topological photonics have the advantage of not requiring strong magnetic fields, and feature intrinsically high-coherence, room-temperature operation and easy manipulation” says Peruzzo.

“These are essential requirements for the scaling-up of quantum computers.”

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Making light work of quantum computing

Light may be the missing ingredient in making usable quantum silicon computer chips, according to an international study featuring #CQC2T Professor Timothy Ralph from the University of Queensland.

The team has engineered a silicon chip that can guide single particles of light – photons – along optical tracks, encoding and processing quantum-bits of information known as ‘qubits’.

The experiment, conducted primarily at the University of Bristol, proved that it is possible to fully control two qubits of information within a single integrated silicon chip.

A surprising result of the experiment is that the quantum computing machine has become a research tool in its own right.

“The device has now been used to implement several different quantum information experiments using almost 100,000 different reprogrammed settings,” Professor Ralph said.

“This is just the beginning; we’re just starting to see what kind of exponential change this might lead to.”

The research has been published in Nature Photonics. (DOI: 10.1038/s41566-018-0236-y)

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