Since the start of operating mode of Euro-Q-Exa, Europe’s 54-qubit system, quantum computing at the Leibniz Supercomputing Centre (LRZ) has entered a period of significant change. Over recent months, the former Quantum Computing and Technologies (QCT) department, which successfully integrated several quantum computers with high-performance computing (HPC) systems, transferred a number of responsibilities to partners. As a result, some colleagues moved to other organisations. Since August, computer scientist Tobias Guggemos has been transforming the team into a versatile research group that will explore quantum technologies and their applications from a holistic perspective.

The new head of LRZ’s Quantum Technologies team is approachable and down-to-earth, with a talent for explaining complex and highly abstract topics in an engaging and often humorous way. In this interview, he discusses new challenges and his plans for the future of quantum technologies at LRZ.

How does someone become a quantum computing specialist?
Dr Tobias Guggemos: During my PhD at LMU Munich, I was tasked with preparing a lecture course on quantum computing. To explain the subject to students, I had to immerse myself deeply in the topic, and that sparked my enthusiasm for exploring it further. You inevitably encounter questions of cryptography and security, which were already central to my doctoral research and later became relevant in projects and in supervising Bachelor's and Master's theses. As a postdoctoral researcher, I was able to apply my expertise at the Faculty of Physics at the University of Vienna and at the German Aerospace Center’s Institute of Earth Observation, where colleagues and I developed technology to bring a quantum processor into space.
Why am I at LRZ? Now we have reached the point where quantum computing is genuinely becoming part of everyday practice. Computing power is advancing rapidly, and the systems here are beginning to be used for the first demanding applications. There are still many open questions, which is exactly why I am at LRZ. We work with a variety of quantum technologies, help users push them to their limits, and gain valuable experience that improves our understanding of both hardware and software.

What do you find particularly fascinating about quantum computing?
Guggemos: For me, the most fascinating concept is still entanglement. At its core, it is a rather simple mathematical concept, yet it has enormous implications for technology and quantum systems. Entanglement, superposition, and quantum states are notoriously difficult to explain. I still have not found a way of describing them clearly without resorting to sketches on paper. Yet entanglement underpins every form of quantum advantage, whether in computing, communication, sensing, or sensor technology.

Why would you send a quantum computer into space?
Guggemos: Because you can? (laughs) The project was driven largely by curiosity, nobody had done it before. If you speak about quantum advantages, we should consider all the ways and places in which it might be used. There were also practical considerations. The satellite industry increasingly aims to perform computations as close as possible to the data source, an approach known as edge computing. Communication with satellites is expensive and difficult to maintain continuously due to the distances involved. Publicly funded organisations such as the DLR operate ground stations, but communication is only possible when a satellite is within range. If larger volumes of data need to be transferred, communication time quickly becomes a bottleneck because of the short overflights and additional capacity must be purchased. The alternative is to equip satellites with computing capabilities. Organisations such as DLR, which collect image datasets of several gigabytes, therefore have a strong incentive to preprocess or analyse data directly on board to save time and costs. In future, quantum computers may play a role here, as they promise advantages in data processing.

Does the technology still work?
Guggemos: The prototype on the satellite consisted of a camera whose images were analysed by a quantum processor directly on site. If you take that concept further, the computer could simply transmit the results of the analysis, such as the GPS coordinates of a wildfire. And yes, the satellite is still operating. The camera is still functioning as well. Unfortunately, the processor is not.