From the Hofburg cellars in Vienna via the Canary Islands to the Beutenberg in Jena

Congratulations on being appointed to the professorship of "Experimental Quantum Information", Prof. Dr. Steinlechner. For those who don't know you yet, could you please give us a brief overview of your academic career?

"Thank you very much! I completed my degree in technical physics in Vienna in 2009, where I also wrote my diploma thesis at the Institute for Quantum Optics & Quantum Information (IQOQI) under the supervision of Anton Zeilinger.  I then did my doctorate in the optoelectronics group at the Institute of Photonic Science ICFO in Barcelona under the supervision of Valerio Pruneri. My research topic was the development of quantum light sources for space applications. After my PhD in 2015, I returned to the Academy of Sciences in Vienna as a postdoctoral researcher to join the group of Rupert Ursin and work on a series of experiments on quantum communication and fundamental aspects of quantum nonlocality. In August 2018, I was appointed as a junior research group leader at Fraunhofer IOF through the Fraunhofer Attract program with my research program "Photonic Technologies for Quantum Communication". Thanks to the unique framework conditions in Jena and the rapid growth in application-oriented quantum photonics in Germany, the group is well positioned within the Fraunhofer IOF. Thanks to the unique framework conditions in Jena and the rapid growth in application-oriented quantum photonics in Germany, the group has grown to 30 employees in just 5 years."

What have been the highlights of your scientific career so far?

"In my scientific career, I have had the privilege of working with leading experimental physicists, theorists and technologists who understand science, education and technology in very different ways. This has not only helped me in terms of content, but has also shaped my approach to research and ultimately my leadership style.

One highlight was certainly the opportunity at the Institute of Quantum Optics and Quantum Information to experience first-hand how Anton Zeilinger, who received the Nobel Prize for experiments with entangled photons in 2022, inspires innovation among his colleagues. During my diploma thesis, I was able to gain my first experience with entangled photons there and later, as a postdoc, I was involved in fundamental experiments on the non-locality of entangled particles. I also remember with pleasure the special locations where we ran experiments, such as on the Canary Islands doing quantum communication over a distance of 144 km between La Palma and Tenerife - at that time it was the longest distance bridged for such experiments - or experiments on quantum non-locality in the cellars of the Vienna Hofburg. These experiences had a special appeal, above all because we were able to make a further contribution to the experimental disproof of Einstein's concept of local realism and the validity of the predictions of quantum mechanics with a test of "Bell's inequality".

Another highlight was my time at the ICFO in Barcelona, where I was able to make a large variety of contacts and learned a lot from my doctoral supervisor about the implementation of complex R&D with limited resources. During this time, I worked intensively on the challenges of quantum communication and the space feasibility of photonic quantum technology. This work later led me to Jena, where I worked in an advisory position on the development of a satellite-compatible source at Fraunhofer IOF.

A key event for me was certainly my appointment as group leader at Fraunhofer IOF - and the launch of the QuNET initiative immediately after my arrival in Jena. The aim of this initiative is to create the physical and technical basics for a quantum-safe government network in Germany. In a series of demonstrator experiments, my team was able to show the practicability of quantum entanglement for quantum communication in fiber and free-beam links."

What exactly does your work in experimental quantum information involve?

"My work is about generating and manipulating quantum states of light and making them usable for various applications. One focus is on the realization of quantum networks. We investigate the entanglement of photons over long distances and develop protocols based on this for secure communication. We are also working on the development of technologies for measurement technology and quantum computers."

How do you see the significance of your research for the future of information and communication technology?

"Quantum physics offers enormous potential for information and communication technology. By using quantum networks, we can transmit data with absolute safety and create new possibilities in distributed information processing. In addition, quantum computers have the potential to perform complex calculations much faster than conventional computers."

What are you most looking forward to in your role as a professor?

"I'm looking forward to helping to actively shape and support the solution of theoretical and technical problems. I now see myself primarily guiding my colleagues through their research projects, designing new experiments and passing on my knowledge. I would also love to be involved in the lab or on the computer.

I have learned that it is important to create space for ideas to be formed, to pursue interests and at the same time to promote and strengthen personal responsibility. This should also involve one's own colleagues, so that everyone benefits from each other and this helps a subject or technology to progress: Experimental Quantum Information = Team Sport - only in a good team can everything flow.

My personal conviction is also that this interest is particularly useful and far-reaching if you also think about the development of technologies beyond the doctorate and make the new findings accessible to everyone. "

How do you see the importance of experimental quantum information for future technologies and applications? And what potential impact could it have on society?

"I think that quantum information has a special place in society in many areas. On the one hand, it enables practical applications in the medium future, which I hope will become state-of-the-art solutions. Then this fascinating and initially unfamiliar technology will become part of everyday life for many people. When terms such as quantum entanglement and quantum superposition enter common language, new perspectives and completely different application possibilities will be opened up. We are currently only scratching the surface of what is possible.

However, such future perspectives should be approached with a realistic timeline and expectations. In addition to many conceptual challenges, quantum technology also places immense demands on the underlying technological basis - in order to gain new insights and carry out revolutionary experiments, numerous highly developed components are required. And this also shows very clearly how theory and experiment are intertwined: only when I can build the corresponding experimental setups and new experimental devices can I verify the theory - but for that I need the theory.

In order for fundamental progress to be translated into quantum applications with added value for society, close cooperation between different disciplines - e.g. computer science, materials science, engineering - is required in addition to the bridge between theory and experiment. I think that Jena offers particularly fertile ground due to the historically proven synergy between basic research and application. I hope to make a contribution in this field of tension between basic research and application.”

What advice or recommendation do you have for students who are interested in experimental quantum information as a field of research?

"Quantum technology is a very interdisciplinary field of research. Therefore, I can only give the following advice: Learn as much as you can about topics you need but in the first step not more than necessary. You should be broad enough for experimentation and research. You should follow your interests fully and only bring the idea of application into the game later. It is difficult to assess the possibilities for applications at the beginning of your research.

Another important point is that experiments today are so complex that they cannot be managed by a single person - open communication and respectful interaction as the basis for good teamwork are therefore just as essential."

Are there any current trends or developments in quantum information that you consider to be particularly promising?

"One promising trend in quantum information is research into quantum networks. This involves the entanglement of quantum states over long distances and the development of protocols for the secure transmission of quantum mechanical information. There are still many fundamental questions in this area, and I'm looking forward to further insights and surprises that await us in the future."

Thank you very much for the interview and good luck with your work here at the Institute of Applied Physics!