FWO travel credit for a short period of study at the Nordita, Nordic Institute for Theoretical Physics (R-6053)

The topic of this short stay is on stochastic thermodynamics. Stochastic thermodynamics is a new field of research, which has radically changed our understanding of non-equilibrium processes in physics and chemistry. The developments are characterized by the common idea to adapt and generalize concepts from equilibrium thermodynamics to the non-equilibrium realm, typically on the level of single particle trajectories monitored over the entire system evolution. Thermodynamic concepts such as heat, work, entropy production, efficiency etc. have hence taken a meaning for small systems on the micro- and nanometer-scale, where thermal fluctuations are omnipresent. For instance, it has been realized that the Onsager reciprocity relations are but a different aspect, close to equilibrium, of a family of much more general relations which hold also far from equilibrium, and which are now known as fluctuation theorems. We will focus on the recent developments concerning the efficiency of small machines. For those machines, the efficiency of energy conversion becomes a stochastic quantity. The following remarkable result was recently discovered: for long but finite running times, the reversible efficiency (eg. Carnot efficiency) is least probable (in the sense of large deviations). This property is an immediate consequence of the fluctuation theorem. During the short visit we plan to investigate an important class of small machines, namely Brownian and molecular motors. They form an active field of research, because of their great importance in biological systems on the (sub-) cellular level, and as artificially fabricated micro-devices. The size of these machines on the micrometer scale and below makes it necessary to include stochastic elements in their description for modeling the effect of thermal fluctuations. Hence the power in- and output, and also the efficiency, are strongly fluctuating quantities. Understanding the properties of these fluctuations is of key importance for both technological and biological applications.

Keywords:STOCHASTIC PROCESSES, Thermodynamics

Disciplines:Mathematical sciences and statistics, Physical sciences