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HL: Fachverband Halbleiterphysik
HL 22: Quantum dots and wires: Transport properties
HL 22.3: Vortrag
Dienstag, 2. April 2019, 14:30–14:45, H34
A quantum-dot heat engine operating close to the thermodynamic efficiency limits — •Martin Josefsson, Artis Svilans, Adam Bruke, Eric Hoffmann, Sofia Fahlvik, Claes Thelander, Martin Leijnse, and Heiner Linke — NanoLund and Solid State Physics, Lund University, Sweden
Particle-exchange heat engines work by using an energy filter to control a thermally driven particle flow between two or more reservoirs at different temperatures. These engines have been predicted to reach the same ideal thermodynamic efficiency limits as those accessible to classic cyclical engines, but this prediction has never been verified. In this work1 we realize a thermoelectric particle-exchange heat engine based on a quantum dot embedded in a InAs/InP nanowire. We demonstrate an electronic efficiency at maximum power close to the Curzon-Ahlborn efficiency and at the maximum efficiency (≈ 70% of Carnot efficiency) the QD still produces finite power output equal to roughly half of the maximal amount.
These results were obtained by measuring the engine’s steady state power output and combining it with the calculated electronic heat flow. This procedure is made possible by an excellent agreement between the modeled and measured generated current, which allows for a quantitative estimate of the heat flow.
[1] Josefsson et al. Nature Nanotechnology 13, 920 (2018)