Prof. Dr. Janik Wolters

Physical foundations of IT security

Quantum communication is for most people a concept they associate with the future. Professor Dr. Janik Wolters is a step ahead: Wolters, who is professor of Physical Foundations of IT Security at TU Berlin, the German Aerospace Center (DLR) and the Einstein Center Digital Future (ECDF), is researching the technological possibilities for securing quantum communication against eavesdropping, even over long distances.  
The Berlin-born scientist studied physics at TU Berlin and wrote his Diplom thesis in theoretical physics on semiconductor devices based on quantum dots, and how these can be simulated on the computer. “A very exciting, but also very theoretical, topic. What I missed, above all, was the practical work on experiments aimed at verifying the calculations,” says Wolters.
After this theoretical work, he therefore found himself drawn to experiments: “Following my studies at the Institut d’Optique in Palaiseau, France, I had a go at experimenting with the quantum physics of individual atoms before returning to Humboldt-Universität zu Berlin for my doctorate.” As part of his doctoral studies, Wolters worked on quantum systems based on artificial atoms. In nanometer-sized diamonds, he investigated individual color centers that behave in a similar way to single atoms. “The goal was to embed these color centers in optical resonators in order to amplify the light-matter coupling.” Following a postdoctoral stay at TU Berlin, Wolters switched to Professor Dr. Philipp Treutlein’s Quantum Optics Lab at the University of Basel (Switzerland) with a Marie Skłodowska-Curie Individual Fellowship from the European Commission. “By that stage, I had already devoted myself to various quantum systems. In Basel, I researched how, and if, these different quantum systems could be combined to form a hybrid system.”

On 1 July 2019, Janik Wolters took up his professorship in Berlin. His research focuses on the development and investigation of quantum memories and quantum light sources, that is to say, on key components in quantum technology. “In contrast to the amplifiers in traditional telecommunication, there are no quantum amplifiers in quantum communication. This is why quantum communication can currently only cover a range of 100 kilometers. To exceed this distance in the future, various concepts have been put forward. One of these concepts is based on so-called quantum repeaters as an analog to the traditional amplifier. Quantum repeaters work with pairs of photons instead of single photons. Researchers have made theoretical proposals in this regard and conducted experimental preliminary work, but so far no working quantum repeater has ever been realized. What is missing, among other things, is one important component, namely, a quantum memory. The development of such quantum memories is one of my main areas of research,” says Wolters.
In his work in Berlin and at the ECDF, Wolters has almost ideal conditions for this purpose: “Anyone wanting to develop secure communication, absolutely has to have contact to prospective users and related technologies. In this respect, I anticipate an intensive exchange of ideas with my colleagues at ECDF.” (kj)