Humboldt-Universität zu Berlin - Mathematisch-Naturwissen­schaft­liche Fakultät - Institut für Physik

Herr Prof. J. Miguel Rubi (Department of Fundamental Physics, Universität Barcelona, Spanien) spricht zum Thema "Microsystems far-from-equilibrium".

Abstract: Many important processes at the microscale require far-from-equilibrium conditions to occur, as in the functioning of biomolecules, molecular motors, nanomotors, and active particles. The non-equilibrium processes taking place in those systems are strongly influenced by the presence of fluctuations. Building up a mesoscopic dynamics compatible with thermodynamics is a subject of primary importance. Thermodynamics provides the basis for understanding how heat and work are related and the general rules that the macroscopic properties of systems at equilibrium follow. Concepts of everyday use such as energy, heat, and temperature have acquired a precise meaning after the development of thermodynamics. Outside equilibrium and away from macroscopic regimes, most of those rules cannot be applied directly. In this talk, I present recent developments that extend the applicability of thermodynamic concepts deep into mesoscopic and irreversible regimes. A probabilistic interpretation of thermodynamics together with probability conservation laws can be used to obtain Fokker-Planck equations for the relevant degrees of freedom. This approach provides a systematic method to obtain the stochastic dynamics of a system directly from its equilibrium properties. A wide variety of situations can be studied in this way, including nonlinear transport in the presence of potential barriers, activated processes, slow relaxation phenomena, and basic processes in biomolecules, such as translocation and stretching.

[1] J. M. Rubi, The long arm of the second law, Sci. Am., 299, 62 (2008)

[2] D. Reguera, J.M. Rubi, J.M. Vilar, J. Phys. Chem. B, 109, 21502 (2005)

[3] R. de Miguel, J.M. Rubi, J. Phys. Chem. B, 120, 9180 (2016)

Plakat zum Kolloquium (pdf)