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arXiv · 1701.07478

Third Law of Thermodynamics as a Single Inequality

Henrik Wilming·Rodrigo Gallego
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Abstract

The third law of thermodynamics in the form of the unattainability principle states that exact ground-state cooling requires infinite resources. Here we investigate the amount of non-equilibrium resources needed for approximate cooling. We consider as resource any system out of equilibrium, allowing for resources beyond the i.i.d. assumption and including the input of work as a particular case. We establish in full generality a sufficient and a necessary condition for cooling and show that for a vast class of non-equilibrium resources these two conditions coincide, providing a single necessary and sufficient criterion. Such conditions are expressed in terms of a single function playing a similar role for the third law to the one of the free energy for the second law. From a technical point of view we provide new results about concavity/convexity of certain Renyi-divergences, which might be of independent interest.

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Henrik Wilming, Rodrigo Gallego. 2017-11-27. Third Law of Thermodynamics as a Single Inequality. https://doi.org/10.1103/physrevx.7.041033

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