Uploaded July 2018 | Updated September 2026, 5 hours ago
Sadi Carnot’s theorem regarding the maximum efficiency of heat engines famously states that the maximum efficiency depends only on the temperature of the heat baths used by the engine – but not the specific details on how these baths are actually realized. Carnot’s results can be derived as a consequence of the second law of thermodynamics. However, in the quantum nanoscale regime, we show that these results demand revision, in particular, more information about the bath other than its temperature is required to decide whether maximum (Carnot) efficiency can be achieved. Moreover, for qualitatively different characterizations of the energy/work extracted, the maximum achievable efficiency of quantum heat engines can be either sub-Carnot, or even exceed Carnot efficiency. This highlights the importance of carefully distinguishing work and heat, especially for a heat engine that operates in the nanoscale quantum regime.
Annual UWO Philosophy of Physics Conference
Thermodynamics as a Resource Theory: Foundational and Philosophical Implications
June 20-22, 2018
philphysics.uwo.ca
Nelly Ng, Freie Universität Berlin, Department of Physics
Visit the Rotman website for more information on applications, events, project descriptions, and openings. rotman.uwo.ca
Follow The Rotman Institute on Twitter: twitter.com/rotmanphilo
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Sadi Carnot’s theorem regarding the maximum efficiency of heat engines famously states that the maximum efficiency depends only on the temperature of the heat baths used by the engine – but not the specific details on how these baths are actually realized. Carnot’s results can be derived as a consequence of the second law of thermodynamics. However, in the quantum nanoscale regime, we show that these results demand revision, in particular, more information about the bath other than its temperature is required to decide whether maximum (Carnot) efficiency can be achieved. Moreover, for qualitatively different characterizations of the energy/work extracted, the maximum achievable efficiency of quantum heat engines can be either sub-Carnot, or even exceed Carnot efficiency. This highlights the importance of carefully distinguishing work and heat, especially for a heat engine that operates in the nanoscale quantum regime.
Annual UWO Philosophy of Physics Conference
Thermodynamics as a Resource Theory: Foundational and Philosophical Implications
June 20-22, 2018
philphysics.uwo.ca
Nelly Ng, Freie Universität Berlin, Department of Physics
Visit the Rotman website for more information on applications, events, project descriptions, and openings. rotman.uwo.ca
Follow The Rotman Institute on Twitter: twitter.com/rotmanphilo
Like The Rotman Institute on Facebook: facebook.com/rotmanphilosophy
Subscribe to our channel: youtube.com/user/rotmanphilosophy










