Berlin 2008 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 16: SYMPOSIUM Driven Soft Matter I

CPP 16.2: Invited Talk

Tuesday, February 26, 2008, 10:00–10:30, C 130

Stochastic thermodynamics of driven soft matter — •Udo Seifert — II. Institut fuer Theoretische Physik,Universitaet Stuttgart

Stochastic thermodynamics provides a conceptual framework for describing small systems embedded in a heat bath and mechanically or by external flow driven to non-equilibrium. Both the first law and entropy production can be consistently defined along single trajectories. An infinity of integral fluctuation theorems hold, among which the Jarzynski relation and the one on total entropy production are prominent ones [1]. After briefly reviewing and illustrating these foundations using a driven colloidal particle as paradigm, I will present within this scheme our recent work concerning (i) optimal finite-time processes and (ii) extended fluctuation-dissipation theorems (FDTs) and generalized Einstein relations. The optimal protocol of an external control parameter minimizes the mean work required to drive the system from one given equilibrium state to another in a finite time. Explicit solutions both for a moving laser trap and a time-dependent strength of such a trap show finite jumps of the optimal protocol to be typical both at the beginning and the end of the process [2]. The Einstein relation connecting diffusion constant and mobility is violated beyond the linear response regime. Based on our recent extension of the FDT [3], we have derived and measured an additive correction term which involves an integral over measurable correlation functions [4].

[1] U. Seifert, PRL 95: 040602, 2005. [2] T. Schmiedl and U. Seifert, PRL 98: 108301, 2007. [3] T. Speck and U. Seifert, EPL 74: 391, 2006. [4] V. Blickle, T. Speck, U.S., C. Bechinger, PRL 98: 210601, 2007.