Fluctuations of the total entropy production in stochastic systems

Fluctuations of the total entropy are experimentally investigated in two stochastic systems in a non-equilibrium steady state: an electric circuit with an imposed mean current and a harmonic oscillator driven out of equilibrium by a periodic torque. In these two linear systems, we study the total entropy production which is the entropy created to maintain the system in the non-equilibrium steady state. The fluctuation theorem holds for the total entropy production in the two experimental systems, both for all observation times and for all fluctuation magnitudes. Copyright (c) EPLA, 2008.