Around 350 guests flocked to the Bavarian Academy of Sciences and Humanities on the evening of 19 February to be taken on a quick ride through the history of quantum physics by Prof. Rainer Blatt. Starting with the physical foundations and initial considerations of various physicists around 1900, which were given a standardized framework in 1925 with the formulation of quantum mechanics, Blatt took the audience through the past 100 years and the constant further development of the theory right up to its implementation in commercial products. The list of technologies that are well known to the public – GPS, magnetic resonance imaging, semiconductors, lasers and many, many more – is long. However, the fact that these technologies are also based on quantum physics phenomena was probably new to some of the audience.
Experimental physicist Blatt has been conducting research in the field of quantum optics and quantum information for many decades and was therefore able to embellish his lecture with anecdotes from his career. He was one of the first to observe a quantum leap, the transition from one energy state of an atom to another, in the laboratory. He has the audience laughing on his side when he jokes that the term ‘quantum leap’ is used colloquially to describe a major advance or breakthrough, whereas an actual quantum leap is the smallest conceivable physical change.
Finally, Blatt arrives in the present and talks about current developments that are based on the targeted control of individual quanta and the utilization of their special properties for innovative technologies such as quantum computing. The fact that this is based on the ability of quantum particles to superposition and entanglement is what Blatt would like the audience to take away with them. „My talk is called ‘and this is just the beginning’,” says Blatt, „and that's something I really believe in.“ Technology for quantum cryptography is already commercially available, but Blatt also believes that quantum simulation and powerful quantum computers that can be used for a wide range of applications are realistic in the coming years and decades, because „there is no law of physics that tells me it can't be done.“
Numerous questions from the audience
After approximately one hour – a surprisingly short time considering the wealth of information - Blatt ends his lecture to answer the numerous questions from the audience. These ranged from fundamental questions – what kind of spatial or temporal extension do quanta actually have – to inquiries about the status of quantum cryptography or the connection between quantum computing and machine learning.
At the same time, it is always important for Blatt to manage expectations. Despite all the justified optimism that the physicist honestly and wholeheartedly advocates, it is important not to get carried away by hype and to allow sufficient time for development. A question from the audience followed on from this, asking why the field is progressing so slowly compared to nuclear research in the past, for example. „That's a matter of perspective,“ Blatt replies with a laugh. In hindsight, many developments appear more straightforward than they actually were. And he is counting on the next generation of scientists. Perhaps a young doctoral student will soon come into play, with a fresh eye and a new approach that has the potential to fundamentally change the field.
Things get personal at the very end when Rainer Blatt is asked what he would like to achieve or experience as an experimental physicist. He doesn't have to think about it for long: calculating a problem from quantum chromodynamics or simulating it with a quantum computer. Or, to put it more generally: normally, findings from research would be used to develop new technologies. However, he would now like to use the technologies developed to answer questions from research. There is spontaneous applause in the room for the passion and enthusiasm that can clearly be heard in his answer.
All other events in the “MQV-Einblicke” series with links to registration can be found here: https://www.munich-quantum-valley.de/quantum-2025/mqv-einblicke
An overview of all other activities organised by the MQV and its partners to celebrate the International Quantum Year can be found here: https://www.munich-quantum-valley.de/quantum-2025