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Scaling Down the Laws of Thermodynamics Chris Jarzynski

Thursday, March 8, 2018 - 11:15 to 12:30 Auditorium

Thermodynamics provides a robust conceptual framework and set of laws that govern the exchange of energy and matter. Although these laws were originally articulated for macroscopic objects, nanoscale systems often exhibit “thermodynamic-like” behavior – biomolecular motors convert chemical fuel into mechanical work, and individual polymer molecules exhibit hysteresis and dissipation when stretched and contracted. To what extent can the laws of thermodynamics be “scaled down” to apply to individual microscopic systems, and what new features emerge at the nanoscale? I will review recent progress toward answering these questions. The second law of thermodynamics is traditionally stated in terms of inequalities. For microscopic systems these inequalities can be replaced by stronger equalities, known as fluctuation relations, which relate equilib-rium properties to far-from-equilibrium fluctuations. The discovery and experimental validation of these rela-tions has stimulated interest in the feedback control of small systems, the closely related Maxwell demon par-adox, and the interpretation of the thermodynamic arrow of time. These developments have led to new tools for the analysis of non-equilibrium experiments and simulations, and they have refined our understanding of irreversibility and the second law. I will also discuss challenges and open questions, including how to extend fluctuation relations to quantum systems, and how to formulate the first law of thermodynamics properly, when the interaction energy be-tween the system and its thermal surroundings cannot be neglected.