From Hay Fever to the Scientific Foundation of Modern Quantum Physics
Exactly one century ago, Werner Heisenberg made scientific history on the North Sea island of Helgoland. His stay there – originally an attempt to escape his hay fever – is considered the birthplace of quantum mechanics. This theory underpins numerous technological achievements: from lasers and semiconductors to modern communication technologies. To honor this important milestone, quantum scientists from around the world gathered in June for an international workshop. The focus was on exchange at the interface between fundamental research and technological applications of quantum mechanics.
The year 2025 has been declared the International Year of Quantum Science and Technology by the UN General Assembly under the leadership of UNESCO. A hundred years ago, Werner Heisenberg achieved a breakthrough on Helgoland with the development of matrix mechanics – the first mathematical formulation of modern quantum theory. This was reason enough for an international symposium with the participation of the Max Planck Institute for the Science of Light (MPL), which drew many leading minds in quantum research to the island. Among them were four Nobel laureates in Physics: Alain Aspect (2022), Serge Haroche (2012), David Wineland (2012), and Anton Zeilinger (2022).
In an interview with Professor Florian Marquardt, Managing Director of the Max Planck Institute for the Science of Light and Director of the ›Theory Division‹, and Professor Birgit Stiller, Leader of the research group ›Quantum Optoacoustics‹, we learn more about the significance of the symposium and their impressions on site.
Professor Marquardt, you were one of the main organizers of the event “100 YEARS OF QUANTUM MECHANICS,” alongside Časlav Brukner (IQOQI, Vienna), Steven Girvin and Jack Harris (both YQI, Yale). How did this come about?
Prof. Marquardt: “In 2019, my colleague Jack Harris – whom I have worked with for a long time – mentioned that 2025 would mark a special anniversary and suggested organizing a conference on Helgoland. In 2020, during the first phase of the pandemic, we began seriously planning by reserving the Nordseehalle. I’ve never organized a conference with such a long lead time, but it certainly helped us to bring together such a high-profile group of experts from around the world as invited speakers and panel participants.”
For laypeople, the quantum world is elusive – at times even strange. What motivated you to dive into this field, and what fascinates you about it?
Prof. Marquardt: “At first, it was simply the fundamental mysteries of the field that excited me. Over time, I also became interested in applications, which today are no longer confined to laboratories but are finding their way into modern technologies.”
As director of MPL, you also lead the Theory Division. Could you briefly outline the role of quantum science in your department and describe your research focus?
Prof. Marquardt: “My research group currently focuses on the interface between artificial intelligence and physics. A key application of AI is in quantum physics. For instance, AI can help make quantum computers significantly more powerful by automatically discovering new methods of error correction. AI can also invent novel experimental building blocks for quantum technologies. We've even applied AI to fundamental puzzles – such as the strange correlations between distant particles in the Einstein-Podolsky-Rosen experiment.”
Professor Stiller, you head the Quantum Opto-Acoustics research group. How did you discover the world of quantum science for yourself?
Prof. Stiller: “My first encounters with the quantum world were during my postdoc, when we were ‘hacking’ quantum communication systems. Today, my team and I are interested in the interaction between light and sound waves in the quantum realm – implementing concepts for quantum technologies, such as quantum memory based on acoustic waves or entanglement between photons and phonons. For example, we investigate how quantum states can be transferred from optical fibers into acoustics and back. We’re also exploring optical neural networks, which we try to control using sound waves – something we call opto-acoustic neuromorphic computing.”
The Helgoland event attracted many renowned scientists. What were your personal highlights from the program?
Prof. Marquardt: “It was striking to see that even after a century, debate remains over the interpretation of quantum foundations. This was evident in both the public panel discussions and the lectures – several of which were given and attended by Nobel laureates. I am also fascinated by how rapidly applications are progressing. For example, impressive results in quantum computing with cold atoms were shared.”
Prof. Stiller: “I was impressed by the diversity of talks – from foundational interpretations to the latest experimental developments. One talk, ‘A Journey of Quantum Information’, presented a thought experiment imagining what history would look like if quantum mechanics had been discovered at a different point in time. And Helgoland is such a small island – we kept running into each other at lunch, dinner, or during walks on the Oberland, just like Heisenberg once did. These moments sparked spontaneous and inspiring discussions, often prompted by the talks or questions from participants. The conference almost felt like a summer school – for professors.”
Professor Rainer Blatt, Scientific Director at IQOQI and Professor of Experimental Physics at the University of Innsbruck, gave a public lecture for the island’s general audience. How important are events like this?
Prof. Marquardt: “This lecture was a way to give back to the residents of Helgoland after we essentially took over their island for a week. Rainer Blatt is an outstanding speaker, and his explanations of ion-based quantum computers were met with lively interest. I believe outreach of this kind is extremely important – it helps society better understand the direction science is heading.”
The conference was both a journey into the past and a look toward the future. Which aspect stood out more for you personally?
Prof. Stiller: “The juxtaposition of both. It’s important to understand the past, but it’s also fascinating to see how far experiments have progressed. Students in physics today receive excellent scientific training – but often know little about the people behind the discoveries and their stories. This conference bridged that gap beautifully, bringing together researchers and communities that rarely meet.”
Prof. Marquardt: “The historical part –highlighted in several talks and remarks – was informative. However, the main focus was clearly on current developments, both in fundamental research and in many application areas. Overall, it was an event that probably only happens in this form once in a lifetime – something truly special.”
Conference organization:
The symposium was initiated and organized by Florian Marquardt (MPL), Časlav Brukner (IQOQI Vienna), Steven Girvin (YQI, Yale), and Jack Harris (YQI, Yale). The organizers gratefully acknowledge the support of their respective institutions – in particular, the Max Planck Institute for the Science of Light (MPL) and the Yale Quantum Institute (YQI) – in hosting parts of the event and assisting with the logistics. Further information about the conference can be found on the Helgoland 2025 website.
