We Demonstrated Photonic Quantum Communication Between Two Quantum Nodes. Is the Quantum Internet Next?

The non-profit Institute of Photonic Sciences (ICFO) recently created a “hybrid” quantum network link and demonstrated photonic quantum communication between two distinct quantum nodes. Professor Hugues de Riedmatten, Catalan Institution for Research and Advanced Studies (ICREA), whose research interests are in quantum information science (QIS) and quantum optics, led the research team.  Previously, researchers had only been able to reliably transfer quantum states between identical nodes.  The ICFO team solved the challenge of a reliable transfer of quantum states between different quantum nodes via single photons.

In the ICFO framework, the nodes essentially function at different wavelengths and bandwidths. What does that mean in English? “It’s like having nodes speaking in two different languages. In order for them to communicate, it is necessary to convert the single photon’s properties so it can efficiently transfer all the information between these different nodes,” explained Nicolas Maring (Ph.D. Candidate, ICFO) in a recent interview with phys.org.

Playing the role of Captain Obvious, Professor de Riedmatten said, “Being able to connect quantum nodes with very different functionalities and capabilities and transmitting quantum bits by means of single photons between them represents an important milestone in the development of hybrid quantum networks.”

How Stuff Works

He’s understating it a bit, because what they actually did was pretty bad-a$$.  They generated a qubit, i.e., a single encoded photon. They converted its wavelength just to show they could be compatible with current telecom technology. Then they transmitted it via optical fiber to another lab, where they converted the wavelength again to be compatible with the receiving node. The qubit transferred its state to the receiving node, which held it for 2.5 microseconds, and the team was able to retrieve its data successfully.

I’m a mid-level nerd, so this kind of thing gets me going. Not because I dream of a “quantum Internet,” but because of the potential applications for this research in quantum computing. Now two different quantum systems can communicate via a single photon. I’m thinking clock synchronization, secure data transmission and security, etc.  And eventually, a distributed quantum computing framework. Can you imagine harnessing the power of a network of quantum computers to address some of humanity’s trickiest problems? Sort of like, oh, I don’t know, a quantum Internet?

‍