Prof. Dr. Matthias Krüger
Non-equilibrium Statistical Physics
(Quantum-)thermal fluctuations are a fundamental part of our world, as they influence our daily observed surroundings in many ways. In equilibrium, such fluctuations are well understood in the framework of statistical physics and thermodynamics. In non-equilibrium, however, many of the helpful tools and theorems, employed for equilibrium systems, are not applicable. This makes non-equilibrium on the one hand harder to understand and treat theoretically, but on the other hand often richer in phenomenology and possibilities. Our group aims at improving both the theoretical description and understanding of non-equilibrium fluctuations, mostly in the following fields.Supported by the DFG in SFB1073, we investigate the frictional damping of a small probe moving on or over solid surfaces. Please read our article on the role of layer-structuring of the surface. From this work, one can learn how deep friction "feels" into the solid.
When Brown discovered Brownian motion in 1827, he expected to see motion of living entities. How could he have known that he saw thermal fluctuations? This question is still not settled. We introduced a new observable, the Mean Back Relaxation (MBR), accepted in Nat. Mat. ("in principle"). We can show that it is a marker for broken detailed balance in confinement. In a later work, we introduce MBR for microscopic densities, which is a marker for broken detailed balance in confinement and in bulk systems.