Scientists create first 'topological photonic' chip

Topological photonic chips promise a more robust option for scalable quantum computers

Scientists have developed something called a "topological photonic" chip, which is said to be able to process quantum information, promising a more robust option for scalable quantum computers.

Topological photonics is a growing field that aims to study the physics of topological phases of matter in a novel optical context. It has the advantage of not requiring strong magnetic fields and features intrinsically high-coherence, room temperature operation, and easy manipulation.

In collaboration with scientists from the Politecnico di Milano and ETH Zurich, RMIT University researchers used topological photonics to fabricate a chip with a "beamsplitter" creating a high precision photonic quantum gate.

According to the research behind the study, who were led by RMIT University's Quantum Photonics Laboratory director, Dr Alberto Peruzzo, this is the first time scientists have been able to demonstrate that quantum information can be encoded, processed and transferred at a distance with topological circuits on the chip.

It's also said that the breakthrough could lead to the development of new materials, new generation computers and deeper understandings of fundamental science.

"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," said Peruzzo.

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

These, Peruzzo added, are essential requirements for the scaling-up of quantum computers.

It's a breakthrough because previous research had focussed on topological photonics using 'classical' lase- light. But the topological photonic uses single photons, which behave according to quantum mechanics.

By demonstrating high-fidelity quantum interference, the scientists were able to transmit accurate data using single photons for quantum communications, which is a vital component of a global quantum network.

"This work intersects the two thriving fields of quantum technology and topological insulators and can lead to the development of new materials, new generation computers and fundamental science" added Peruzzo