Fluctuations and major deviations from the Second Principle

The Second Principle of Thermodynamics is a macroscopic theory at the heart of our understanding of irreversible phenomena. At the scale of small systems, such as small biomolecules or mesoscopic conductors, it is constantly violated by fluctuations. A whole series of recent works have made it possible to predict and experimentally verify the statistical properties of these fluctuations, based on very general relations such as Jarzynski's relations or the fluctuation theorem.