Stephanie Wehner awarded the Körber Prize 2025

Text: Sharon Ann Holgate

Stephanie Wehner is a pioneer in quantum networks. The German physicist and computer scientist has developed QNodeOS, the first operating system for quantum computer networks, helping to pave the way for a quantum internet that will revolutionize the way we communicate: promising an increased level of cyber security for all our personal data and financial transactions. Thanks to her work, a network of quantum computers of any physical type can now be programmed to perform tasks without the user needing detailed knowledge of how the computer hardware works. Building on this research, the Körber Prize winner plans to find new applications that will make a small-scale quantum network useful for industry and academia within the next decade.

“My goal is to make the ultimate form of communication allowed by nature – quantum communication – available to all,” says Stephanie Wehner, Antoni van Leeuwenhoek Professor in quantum information at Delft University of Technology in The Netherlands, and winner of the Körber European Science Prize 2025.

Images:

(1) A glimpse inside the quantum computer: The cryostat cools the system to temperatures close to absolute zero – only under these extreme conditions can the delicate qubits be controlled more effectively.

(2) Quantum bits are ephemeral and unstable. They require highly precise measurements, which Stephanie Wehner and her team carry out in the Quantum Network Explorer lab at the QuTech Institute.

(3) Optical quantum network test bed in the QuTech lab: This is where technologies are being developed that will enable completely new forms of networking.

“My goal is to make the ultimate form of communication allowed by nature – quantum communication – available to all,” says Stephanie Wehner, Antoni van Leeuwenhoek Professor in quantum information at Delft University of Technology in The Netherlands, and winner of the Körber European Science Prize 2025.

Wehner, who is also Director of the European Quantum Internet Alliance (QIA) – a collaboration between 42 partners (including 12 academic institutions) – intends to achieve this partly by spearheading the building of a quantum network linking two metropolitan area networks in cities hundreds of kilometres apart by 2030. This prototype network will build on her recent work developing the QNodeOS operating system that allows apps to be developed for, and run on, quantum computers that are networked together. Crucially, QNodeOS removes the need for users of quantum computers to be restricted solely to highly qualified physicists or engineers with a deep knowledge of quantum mechanics. Since none of us would want to hire a system specialist every time we wanted to make an online purchase or run another application, Wehner’s operating system opens up a future quantum internet to a much wider range of users.

“I’m working at the intersection between physics and computer science, and the majority of my research in the last 10 years has been about the ‘moonshot mission’ of creating a quantum internet. We want to make this science into technology.

So one of the key questions was: how can we run programs on this network?” explains Wehner, stressing that addressing this question has been a large undertaking for her and her team. “We spent a lot of time working out how to make such systems programmable for the first time,” she says, pointing that without operating systems our phones and computers would be completely useless.

“Computers only became useful because people could write programs for them. So innovations rely on not just hardware, but also being able to run software on it. I’m really excited that we’ve created the first operating system for quantum networks, and provided a way for users to write their own programs without having to be experts in the quantum computer hardware,” she continues. Wehner describes QNodeOS as being like an outline drawing in a colouring book. “What I find most exciting from a research perspective is that with QNodeOS we created a form of framework to think about how to run applications on a quantum network. But as with doing anything for the first time, it is not perfect and it now creates entirely new research questions in quantum computer science that we did not consider before. Now that we have the outline, we can colour in the picture by tackling those research questions,” she states.

“The development of QNodeOS, the world’s first quantum network operating system, is a game- changer in the early adoption of quantum technology,” says Artur Ekert FRS, Professor of Quantum Physics at the University of Oxford and Founding Director of the Centre for Quantum Technologies in Singapore.

Wehner explains that a new quantum internet would not be a replacement for the ‘classical’ Internet of today, but would instead work alongside it to carry out tasks that are impossible using classical computer communication. “The vision of a quantum internet is to provide a fundamentally new internet technology by enabling quantum communication between any two points on earth,” she explains.

While the potential uses for a quantum internet are yet to be fully realised, future applications could include improved security for the transmission of our financial and healthcare data, providing us withproof that our online data has been deleted, linking remote sensors such as telescopes for better imaging of the sky, and even enhancing the speed at which national electricity grids can direct power to cope with surges in demand. Already a winner of other scientific prizes, Wehner intends using the Körber Prize funding to find new applications aside from data security that will make a small-scale quantum network useful for both industry and academia within the next five to ten years.

But just what is it about quantum computers that will enable them to provide services, including methods of communication, that classical computers are not capable of? This all comes down to how quantum computers operate.

The strange new world of quantum computers

Quantum computing, and in fact quantum technologies in general, are so-called because the way they work is dependent on the behaviour of quanta: which are the smallest discrete packets of energy or matter that can exist. This gives these technologies some unique abilities. Quantum computers, for instance, boast vastly faster processing speeds than classical computers thanks to how they store data. In the computers that power our current digital world, miniscule circuit elements or ‘bits’ represent data in terms of 0s and 1s. When a bit is in the ‘on’ state, holding an electric charge, it represents a ‘1’, but when turned off, with no charge, it represents 0. To process data the individual bits are switched on and off. By contrast, the way that a quantum computer handles data is fundamentally different.

In a quantum computer each of the quantum bits, known as ‘qubits’, which represent the data can be in a combination or ‘superposition’ of both state 0 and state 1 simultaneously, thereby vastly speeding up calculations. Some mathematical problems can already be solved much faster via a quantum computer than by a classical computer. For example a 2019 demonstration of Google’s Sycamore 53-qubit quantum processor solved a mathematical task involving a sequence of random numbers in 200 seconds that would likely have taken a classical supercomputer 10,000 years to complete. So there is enormous scope for many types of calculations and other mathematical problems to be solved by quantum computers. However they are far from being devices that can be readily incorporated into the average office.

This is because today’s quantum computers are made from components very different to those inside your laptop, tablet or phone. Instead of processing information thanks to wires and electronic components including transistors and capacitors, these machines – which are mostly based in academic research labs – have strange architectures; such as ion traps, superconducting circuits, or benches full of lasers. While each separate device is capable of remarkable feats, coupling these curious machines together into a Quantum Internet would enable people outside the world of academic research to access their extraordinary capabilities.

Quantum computers are also able to provide enhanced security for data thanks to another seemingly-strange quantum mechanical effect known as ‘quantum entanglement’. To understand the concept of entanglement, it is first important to realise that objects in the quantum world behave nothing like the objects we see and interact with in our everyday lives. In the quantum domain – a microscopic world where objects measure in at much smaller than the width of a human hair – things can happen that would seem like magic or science fiction if they occurred in our everyday world. We would certainly not expect that flipping a coin in our kitchen would allow us to instantly know the result of a coin flip happening simultaneously on the other side of the world, without any communication between the two locations. But this is exactly the type of behaviour that is observed whenever two quantum particles are in an ‘entangled’ state. When correlated like this, the two particles share a mysterious connection that reveals its nature when you measure one particle. That act of taking a measurement instantly reveals information about the entangled partner, even when the two particles are physically separated over large distances.

An entangled system could, for example, be comprised of two photons (light particles) that each have a correlated polarization. In this case, when we make a measurement to reveal in what way one of these entangled photons is polarized, we immediately know the polarization state of the other photon without measuring it directly – even though no information has actually travelled between the two photons. Quantum mechanics also has another trick up its sleeve: crucially, the value measured is completely random and furthermore is not established in advance of that measurement being made. This ‘correlation’ of truly random outcomes, which does not involve any information being communicated, is what makes quantum entanglement so useful for applications like quantum cryptography. In cryptography, the shared correlations can be used to detect eavesdropping and create secure encryption keys.

One simple method of making computer communication secure is for the sender and receiver to both possess an identical secret key that can encrypt and decrypt data. The downside is that anyone with access to this key can decipher the otherwise unintelligible encoded message. But using quantum entanglement means the key, consisting of a random value, only comes into existence when the entanglement is measured.

In the quantum-secured classical computer networks already used by financial institutions and telecom companies, entangled photons instantaneously share the key for encrypting and decrypting sensitive data, rather than needing to create a key in advance. Anyone eavesdropping on that quantum key is revealed: since trying to read it will change the state of the entangled particles, thereby signalling the hacker’s presence.

Entanglement can occur over distances of many kilometres, and was not believed to be feasible by Albert Einstein. Einstein, along with colleagues Boris Podolsky and Nathan Rosen, described quantum entanglement in a research paper in 1935, but completely dismissed the notion. He famously referred to it later as “spooky action at a distance”. But by the early 1980s, experiments had shown that quantum entanglement is a real phenomenon. Over the next couple of decades, scientists had realised the huge potential entangled particles held for encrypting information and providing enhanced security – a world Stephanie Wehner is familiar with.

From ethical hacking to academic research

It is not often that computer hacking is seen as a positive thing. But Wehner’s background –

which includes two years working part-time as an ethical hacker probing Internet systems to reveal weaknesses for Dutch IT security consulting company ITSX alongside her undergraduate studies in computer science at the University of Amsterdam – gives her a unique insight into the challenges of computer security.

“Hacking is actually science in a very pure form because you try to figure out how something works by an all-out exploration of it,” says Wehner, who worked as a network administrator for Dutch internet service provider XS4ALL prior to university. “Hacking is always easier than making something secure. Because in order to hack a system you only need to find one mistake, but in order to keep things secure you must make sure that there are no mistakes,” she continues, stressing how hard it is to achieve computer security in practice as opposed to just in theory. She feels her ethical hacking background helps her to stay “appropriately critical” of computer systems’ security, “and also to understand that in order to translate this promise of security into the real world it’s important to give people access now. This is not only to develop their own applications, but actually to allow them to gain more confidence of what security in practice means here.”

As part of both her computer science BSc and MSc, Wehner studied physics modules, then combined the two disciplines with her PhD in quantum cryptography. More recently, she has published research probing quantum mechanical effects: including linking fundamental quantum mechanical concepts such as non-locality and the uncertainty principle, and investigating the effects of gravity on quantum mechanical systems. She has also carried out a wide range of quantum information science investigations, including creating a software tool that accurately simulates all aspects of quantum networks and modular quantum computing systems – from their physical hardware to the applications that run on them.

“Stephanie Wehner has been instrumental in advancing quantum information theory and its practical applications,” says Peter Zoller, Professor for Theoretical Physics at the University of Innsbruck in Austria. “She has played a key role in designing protocols for the Quantum Internet, including entanglement-based communication schemes for secure data transmission across long distances,” he continues, adding that Wehner has also addressed quantum mechanics questions “at the foundations of physics”.

Wehner herself acknowledges that her mix of expertise helps give her a deeper understanding of the topics she researches, and to connect the many different parts of a puzzle required to realize quantum networks. “Developing QNodeOS created more computer science questions that I didn’t really consider before. Such as when you build an operating system and multiple programs can run on that, when does each program get to use the resources of the computer?”, she explains, adding that in current classical computers not all the open programs are active simultaneously and a scheduler decides which programs should be taking up resources at any given time. For instance, during a Zoom call most of the computer’s actions will be dedicated to running that call. “I hadn’t really thought about this being a non-trivial problem with entirely new twists in the quantum domain when we started out. So we were ambitious and we also wanted to do multitasking, meaning that several programs can run at once.” The result is an operating system that would enable a network of quantum computers to run tasks while waiting for communication from other computers in their network. As in classical computing, this could be very useful for getting more out of the computers.

Chair of the Körber Prize Search Committee Physical Sciences, and Professor of Solid State Physics at ETH Zurich, Klaus Ensslin praises the breadth of research the prize winner has undertaken. “From her beginnings as a “purely classical hacker” to delving into the foundations of quantum theory, Stephanie Wehner has played a pivotal role in some of the decade’s most ground-breaking [quantum mechanics] experiments. More recently, she has dedicated herself to realizing the vision of a Quantum Internet, marking a truly remarkable scientific journey,” he says.

Image:

(1) Science does not end at the lab bench – in her office, Wehner analyzes research results and writes scientific papers.

(2) Wehner’s daily work also involves a lot of programming: Excerpt from a schematic representation of the implementation of QNodeOS.

A collaborative effort

Wehner explains that her work with the 42 partners based in Europe that make up the Quantum Internet Alliance (QIA) has two main goals: to realise by 2030 a quantum network linking two metropolitan area networks in cities hundreds of kilometres apart, and to enable a European platform for Quantum Internet development. By building this prototype network the QIA aims to develop the beginnings of a pan-European Quantum Internet, she says.

Chiara Macchiavello, Professor of Quantum Computing at the University of Pavia in Italy describes the QIA as “a game changer in the context of quantum communications and [working] towards the development of a Quantum Internet”. She notes how this joint effort “grows Wehner’s precious ability to interact and collaborate with people coming from both academic institutions and industrial environments.”

It is Wehner’s desire to see Europe taking a leading role in developing the Quantum Internet, creating new jobs as well as opportunities for start-up companies and the commercial sector. “I think in Europe we are at the forefront of quantum networking research,” she says, pointing out that her recently published work on QNodeOS was a collaborative effort with scientists in The Netherlands, Austria and France. “We’ve done this for the first time here in in Europe, so we are technologically in a very good position. But the question maybe now is: what does this mean for Europe? I’m very passionate about the European project. So I care a lot that we stay ahead in Europe in science, but also that we build a very strong European ecosystem that can translate this research into a quantum network technology which ultimately benefits Europe in both the societal and economic sense,” Wehner continues.

Reaching out

In addition to continuing to engage with the general public via talks and the mass media, Wehner plans to further raise awareness of the potential for a Quantum Internet by using the 5% of the Körber Prize fund earmarked for outreach work to develop a video game for children that introduces the basics of quantum entanglement. “I like very much that the Körber Prize has the opportunity to spend funding on an outreach project to communicate science; I think that’s fantastic. This prize was an opportunity to put forward an idea that I otherwise would not be sure how to support.”

Previously, via her role as Director of the QIA, Wehner has spearheaded an online outreach project known as the Quantum Network Explorer (QNE). The QNE website allows both beginners and experts to explore a simulated quantum network and, she explains, will enable potential commercial and academic end-users to feed into the development of the Quantum Internet.

Wehner admits to having developed “an obsession with communication” as a child, and this passion, albeit now with a quantum physics slant, shows no signs of diminishing. “If you care about communication and you want to know what is the ultimate form of communication that you could hope to have, and you also believe that the world is described by quantum mechanics then it’s kind of clear that you should be investigating quantum communication,” she explains, adding that she is also driven by a desire to transfer her research from the lab into the everyday. “Wanting my research to become a technology used by as many people as possible is what really motivates me,” she concludes.

The Prize Winner

Stephanie Wehner is a physicist and computer scientist, and Director of the European Quantum Internet Alliance. Born in Germany in 1977, as a child she “became obsessed by communication,” says Wehner. In high school she learned that different computers could communicate with one another, and was inspired by a class trip to a research institute “where people exchanged information through the air optically – I found these things super-fascinating.”

Armed with a home computer and early modem, Wehner began exploring the then newly emerging technology of the Internet. “I was fascinated by how distinct entities or computers exchange information and interact with each other in order to jointly accomplish tasks and do useful things – without actually having a central plan.”

This interest saw Wehner become a Network Administrator in 1997 for Dutch internet service provider XS4ALL, before quitting in 1999 in order to study for a BSc – then later for an MSc – in computer science at the University of Amsterdam, learning further from working part-time alongside her undergraduate studies as an ethical hacker for IT security consulting company ITSX. Remaining in the same university, Wehner studied quantum cryptography for her PhD, which was awarded in 2008.

Her mix of quantum physics and computing skills led to a two-year postdoc in the Institute for Quantum Information and Matter at the California Institute of Technology (Caltech) in the United States, before she became an Assistant Professor, then in 2013 an Associate Professor, in the School of Computing at the National University of Singapore. Wehner concurrently worked as a Principal Investigator at the Centre for Quantum Technologies in Singapore – a position she held until 2016. In 2014, Wehner moved back to The Netherlands to take an Associate Professor role in the research institute for quantum computing and quantum internet QuTech at Delft University of Technology, where she is now Antoni van Leeuwenhoek Professor in quantum information.

Wehner is an elected member of the Royal Netherlands Academy of Arts and Sciences, and co-founder of the largest international conference on quantum cryptography (QCRYPT). She is also a co-founder of the spinout Delft Networks, where she serves as a scientific advisor, and from 2018 to 2022 she served as Elected Science Vice Chair of the Science and Engineering Board of the EU Flagship on Quantum Technologies.

Alongside her research Wehner has spearheaded an online outreach project known as the Quantum Network Explorer (QNE). The QNE website allows both beginners and experts to explore a simulated quantum network and, she explains, will enable potential commercial and academic end-users to feed into the development of the quantum internet – an opportunity she considers “very important for the translation of this research into actual technology.”

Ms Nemela, you joined the Executive Board of Körber-Stiftung earlier this year. What does the Körber Prize mean to you personally?

The Körber Prize is Europe’s most prestigious science award – not only because of its outstanding laureates, but also because of the idea behind it: to honour excellent research from Europe that has the potential to shape our future. What fascinates me most is being drawn into new scientific worlds again and again – each one expanding my sense of what’s possible. One moment it’s about nerve cells, the next about quantum computers. This constant shift between the life sciences and the physical sciences is what makes the prize so stimulating. It reflects the breadth and diversity of scientific discovery and opens doors to ideas that were once beyond imagination.

The Foundation has awarded the Körber Prize for over four decades. How do you explain such lasting commitment?

The prize was initiated by our founder, Kurt A. Körber. He was convinced that research with societal relevance deserves special recognition. As an inventor and entrepreneur, he envisioned the prize with an entrepreneurial spirit from the very beginning – as a way to enable research free from bureaucratic constraints. That’s why our laureates can use the prize money with great freedom. This flexibility – combined with scientific excellence and long-term vision – continues to define the prize to this day. Especially in times of geopolitical unrest, its message is more relevant than ever: science needs freedom, trust, and collaboration across borders.

Why does Stephanie Wehner deserve the prize, and how does her research reflect the spirit of the Körber Prize?

Stephanie Wehner is a standout figure in quantum research – both scientifically and strategically. Together with her team, she developed the world’s first operating system for quantum networks, thus opening entirely new possibilities: applications can now be programmed without requiring one to be a physicist. Her research makes a highly complex field accessible and lays the foundation for future quantum technology applications. She combines scientific depth with visionary thinking – exactly what the Körber Prize stands for.

Taking a step back: how can a science award like the Körber Prize help build a stronger Europe?

Our laureates are more than outstanding researchers – they are role models and drivers of innovation. They demonstrate what becomes possible when creative minds work with courage and passion. Many of them also help shape structures that strengthen Europe’s scientific landscape – just as Stephanie Wehner does with the development of a European Quantum Internet. Thus, the Körber Prize is not merely about individual success stories; it represents a narrative of European science as a collaborative achievement. It is a strong commitment: to research as a collective endeavour and to Europe as a place of freedom and innovation.