Date: 19th October 2011
Time: 12:00h
Place: Aula seminari de física fonamental (3.20)
Speaker: Jordan M. Horowitz (Departamento de Física Atómica, Molecular y Nuclear and GISC, Universidad Complutense de Madrid, Spain)
Title: Thermodynamics with Feedback: Extracting Work from Information
Abstract.-
The laws of thermodynamics restrict the maximum efficiency with which a thermodynamic engine can convert heat into useful work. However, this limit can be overcome with the use of feedback – that is by altering the operational protocol of the engine in response to information about its microscopic state. The reason being that the information acquired through feedback can itself be converted into work. In this talk, I will discuss recent results detailing how information enters into the thermodynamics of a system driven away from equilibrium by feedback, such as a thermodynamic engine. In particular, I will prove and analyze the second law of thermodynamics with discrete feedback, which relates information to heat, work, and irreversibility. We will see that optimal feedback processes that convert all the information into work are feedback reversible – they are indistinguishable from their time reverse. Finally building on the intuition gained from examining the second law of feedback, I will introduce a method for designing optimal thermodynamic engines with feedback, which I will illustrate with an N-particle Szilard engine.
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Horowitz, J. M. and Parrondo, J. M. R., Eurphys. Lett. 95, 1005 (2011)