Practical building blocks for a quantum internet: Page 2 of 2

September 12, 2017 //By Jean-Pierre Joosting
A team of researchers at The Australian National University (ANU), led by Associate Professor Matthew Sellars, have taken a major leap forward to provide practical building blocks for a global quantum internet – by showing that an erbium-doped crystal is uniquely suited to enable a global telecommunications network that harnesses the weird properties of quantum mechanics.

Erbium, a rare earth ion, has unique quantum properties such that it operates in the same band as existing fibre optic networks, eliminating the need for a conversion process.

"The unique advantage of our technology is that it operates in the same 1550 nanometre band as today's telecommunications infrastructure, making it compatible with the fibre optic cables found in existing networks," said first author and PhD candidate Miloš Ranči?.

"We've shown that erbium ions in a crystal can store quantum information for more than a second, which is 10,000 times longer than other attempts, and is long enough to one day send quantum information throughout a global network."

Sellars said the new technology can also be operated as a quantum light source or used as an optical link for solid-state quantum computing devices, connecting them to the quantum internet.

"Not only is our material compatible with existing fibre optics, but it's versatility means it will be able to connect with many types of quantum computers including CQC2T's silicon qubits, and superconducting qubits such as those being developed by Google and IBM," said Sellars.

"This result is so exciting to me because it allows us to take a lot of the in-principle work we've demonstrated and turn it into practical devices for a full-scale quantum internet."


Dr Rose Ahlefeldt and A. Prof Matthew Sellars operating a high resolution dye laser (used to study rare earth crystals) in the solid state spectroscopy laboratory at Australian National University. Image courtesy of ANU/cqc2t.org.

The article can be accessed at: http://dx.doi.org/10.1038/NPHYS4254

http://cqc2t.org