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Portrait of Heiner Linke; Photo: Kennet Ruona

Heiner Linke

Professor, Deputy dean (prorektor) at Faculty of Engineering, LTH

Portrait of Heiner Linke; Photo: Kennet Ruona

A quantum-dot heat engine operating close to the thermodynamic efficiency limits


  • Martin Josefsson
  • Artis Svilans
  • Adam M. Burke
  • Eric A. Hoffmann
  • Sofia Fahlvik
  • Claes Thelander
  • Martin Leijnse
  • Heiner Linke

Summary, in English

Cyclical heat engines are a paradigm of classical thermodynamics, but are impractical for miniaturization because they rely on moving parts. A more recent concept is particle-exchange (PE) heat engines, which uses energy filtering to control a thermally driven particle flow between two heat reservoirs1,2. As they do not require moving parts and can be realized in solid-state materials, they are suitable for low-power applications and miniaturization. It was predicted that PE engines could reach the same thermodynamically ideal efficiency limits as those accessible to cyclical engines3–6, but this prediction has not been verified experimentally. Here, we demonstrate a PE heat engine based on a quantum dot (QD) embedded into a semiconductor nanowire. We directly measure the engine’s steady-state electric power output and combine it with the calculated electronic heat flow to determine the electronic efficiency η. We find that at the maximum power conditions, η is in agreement with the Curzon–Ahlborn efficiency6–9 and that the overall maximum η is in excess of 70% of the Carnot efficiency while maintaining a finite power output. Our results demonstrate that thermoelectric power conversion can, in principle, be achieved close to the thermodynamic limits, with direct relevance for future hot-carrier photovoltaics10, on-chip coolers or energy harvesters for quantum technologies.


  • Solid State Physics
  • NanoLund: Center for Nanoscience

Publishing year







Nature Nanotechnology





Document type

Journal article


Nature Publishing Group


  • Energy Engineering
  • Condensed Matter Physics




  • ISSN: 1748-3387