Stochastic thermodynamics of fluctuating density fields: Non-equilibrium free energy differences under coarse-graining

T. Leonard; B. Lander; U. Seifert; T. Speck

doi:10.1063/1.4833136

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arXiv · 1310.2891

Stochastic thermodynamics of fluctuating density fields: Non-equilibrium free energy differences under coarse-graining

T. Leonard·B. Lander·U. Seifert·T. Speck

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Abstract

We discuss the stochastic thermodynamics of systems that are described by a time-dependent density field, for example simple liquids and colloidal suspensions. For a time-dependent change of external parameters, we show that the Jarzynski relation connecting work with the change of free energy holds if the time evolution of the density follows the Kawasaki-Dean equation. Specifically, we study the work distributions for the compression and expansion of a two-dimensional colloidal model suspension implementing a practical coarse-graining scheme of the microscopic particle positions. We demonstrate that even if coarse-grained dynamics and density functional do not match, the fluctuation relations for the work still hold albeit for a different, apparent, change of free energy.

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T. Leonard, B. Lander, U. Seifert, T. Speck. 2013-10-10. Stochastic thermodynamics of fluctuating density fields: Non-equilibrium free energy differences under coarse-graining. https://doi.org/10.1063/1.4833136

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