Thermodynamic Geometry of Microscopic Heat Engines

Kay Brandner; Keiji Saito

doi:10.1103/physrevlett.124.040602

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arXiv · 1907.06780

Thermodynamic Geometry of Microscopic Heat Engines

Kay Brandner·Keiji Saito

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Abstract

We develop a geometric framework to describe the thermodynamics of microscopic heat engines driven by slow periodic temperature variations and modulations of a mechanical control parameter. Covering both the classical and the quantum regime, our approach reveals a universal trade-off relation between efficiency and power that follows solely from geometric arguments and holds for any thermodynamically consistent microdynamics. Focusing on Lindblad dynamics, we derive a second bound showing that coherence as a genuine quantum effect inevitably reduces the performance of slow engine cycles regardless of the driving amplitudes. To demonstrate the practical applicability of our results, we work out the example of a single-qubit heat engine, which lies within the range of current solid-state technologies.

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Kay Brandner, Keiji Saito. 2019-07-15. Thermodynamic Geometry of Microscopic Heat Engines. https://doi.org/10.1103/physrevlett.124.040602

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