Thermodynamic time asymmetry in nonequilibrium fluctuations

TL;DR

This paper demonstrates that thermodynamic entropy production in nonequilibrium systems can be understood as a consequence of time-reversal symmetry breaking in the statistical description of fluctuations, linking entropy to dynamical randomness.

Contribution

It provides a complete experimental analysis connecting entropy production to the breaking of time-reversal symmetry via dynamical entropies in driven systems.

Findings

Entropy production equals the difference between forward and reverse dynamical entropies.

Time asymmetry in fluctuations underpins thermodynamic irreversibility.

Experimental validation in Brownian motion and electric noise systems.

Abstract

We here present the complete analysis of experiments on driven Brownian motion and electric noise in a $RC$ circuit, showing that thermodynamic entropy production can be related to the breaking of time-reversal symmetry in the statistical description of these nonequilibrium systems. The symmetry breaking can be expressed in terms of dynamical entropies per unit time, one for the forward process and the other for the time-reversed process. These entropies per unit time characterize dynamical randomness, i.e., temporal disorder, in time series of the nonequilibrium fluctuations. Their difference gives the well-known thermodynamic entropy production, which thus finds its origin in the time asymmetry of dynamical randomness, alias temporal disorder, in systems driven out of equilibrium.