Julian Schmitt Wins Rudolf Kaiser Prize

Awarded the Rudolf Kaiser Prize: - (from left)   Julian Schmitt from the Institu
Awarded the Rudolf Kaiser Prize: - (from left) Julian Schmitt from the Institute of Applied Physics and Rainer Lüdtke from the German Foundation Center in the Stifterverband. © Photo: Barbara Frommann/University of Bonn all images in original size .
Dr. Julian Schmitt from the Institute of Applied Physics at the University of Bonn is to receive the 2023 Rudolf Kaiser Prize, one of the most prestigious accolades in Germany for early-career natural scientists working in the field of physics. 

The researcher is being recognized for "developing methods for monitoring quantum gases and measuring the compressibility and equation of state of a photon gas in the quantum range". "Studying how quantum gases behave under readily controllable experimental conditions is key to understanding fascinating quantum phenomena such as room-temperature superfluidity," Dr. Julian Schmitt says.

By combining an innovative method for nanostructuring mirrors with material-filled optical resonators, the physicist has demonstrated that thermodynamic concepts of atomic systems can be extended to photon gases at room temperature, allowing fundamental predictions of statistical physics to be validated for low-dimensional quantum gases. This has enabled him and his team to measure both the compressibility and the equation of state of a photon gas at quantum level for the first time.

The optical quantum gas was generated in a molecule-filled optical microresonator and trapped in a mirror box for light in a way that gave it a spatially uniform density. By exerting precisely regulated forces on the photon gas, the team then succeeded in demonstrating the compressibility of an optical gas for the first time. In particular, they confirmed that this compressibility rises sharply in the quantum range, as the theory had predicted. "This technology for making homogeneous ’light samples’ is opening up some completely new possibilities for investigating quantum matter both in and out of thermal equilibrium and could play a major role in developing quantum-enhanced sensors," Schmitt says.


Julian Schmitt studied physics and gained his doctorate in quantum optics at the Institute of Applied Physics at the University of Bonn before going on to do postdoctoral work at the University of Cambridge’s Cavendish Laboratory in the UK. He returned to Bonn in 2020 to head up the Collaborative Research Center CRC/TRR 185 "Open System Control of Atomic and Photonic Matter" (OSCAR) and has been an independent head of a research group since 2023. In 2022, his research won him an illustrious ERC Starting Grant and the Young Investigator Award presented by the Matter and Light for Quantum Computing (ML4Q) Cluster of Excellence.

About the award:

The ¤30,000 Rudolf Kaiser Prize has been awarded since 1989 to experimental physicists under 40 who have published several exceptional papers but not yet been appointed to a chair or professorship. The foundation that presents the prize was set up by Dr. Rudolf Kaiser in 1987 and is managed by the Stifterverband für die Deutsche Wissenschaft. Born in Nuremberg in 1923, Rudolf Kaiser spent many years working as presiding judge at the Federal Patent Office. He gained his Habilitation in experimental physics at the Technical University of Munich in 1979, where he devoted most of his time to the promotion of early-career researchers.