QuTech researchers present operating system for quantum networks

“We want to make quantum network technology accessible to everyone,” says Stephanie Wehner, Professor of Quantum Computer Science at the Faculty of Applied Sciences, Director of the Quantum Internet Alliance, and lead author of the Nature paper entitled An operating system for executing applications on quantum network nodes.

“We’re not working on quantum computing, we’re purely focused on the quantum internet,” Wehner explains from her car on the way home. “We connect quantum computers and other quantum devices over a network. And now we’ve created an operating system that allows you to actually run a programme on such a network.”

As an example of a network programme, she mentions using a web browser on a laptop to retrieve information from the internet. “One programme is the web browser on your computer, the other is the programme running on the web server. Viewing web pages is done through the interaction between these two programmes. A network application always involves two or more programmes working together.”

What is taken for granted in classical computer networks is now becoming possible for quantum networks thanks to the QNodeOS operating system. “With QNodeOS, we’re taking a big step forward,” says Wehner. “For the first time, it enables easy programming and the running of applications on a quantum network.”

‘QNodeOS acts as the interface between programming languages like Python and the diverse qubits’

A quantum network connects multiple quantum devices and allows them to exchange quantum information. In classical networks, information is transmitted as bits, whereas in quantum networks, it is exchanged using quantum bits (qubits). Last year, QuTech researchers successfully established a quantum link between Delft and The Hague. Quantum networks are expected to form the foundation of a future quantum internet, which experts believe will be inherently secure and unhackable.

QNodeOS acts as the interface between high-level programming languages like Python and the diverse qubits found in quantum devices. As a demonstration, the researchers established a connection between quantum processors in Innsbruck and Delft.

“Our trapped-ion processors here work fundamentally differently from the diamond-based colour centre processors in Delft,” explains Prof. Tracy Northup, a co-author from Innsbruck. “Yet, we’ve demonstrated that QNodeOS works with both and can connect the two types.”

“This first operating system provides a framework for understanding what’s in a quantum network and how it all fits together,” Wehner reflects. “Now that we have this, we’re encountering new research challenges at the intersection of physics and computer science. I find that incredibly exciting. For example, a network programme must be able to switch between applications – a process known as ‘scheduling’ in computer science. We’re only just beginning to understand how scheduling works in a quantum network.”