We study an endoreversible quantum heat engine in which the heat transfer between the baths is mediated by two qubits. Each qubit acts as an energy filter which allows for the conversion of heat into work. The relation between the efficiency and the power output is derived. It is found that the efficiency of the quantum heat engine at the maximum power output is closely dependent on the properties of quantum dots and does not equal the Curzon-Alhborn efficiency, which is only a function of the bath temperatures. The efficiency and the power output may be adjusted through qubit energy levels. It is further shown that in the limiting cases of small energy levels (or high temperatures) and small temperature differences, the quantum heat engine converges to the classical endoreversible Carnot heat engine.

• Received 21 June 2019
• Revised 28 September 2019
• Accepted 11 February 2020

DOI:https://doi.org/10.1103/PhysRevResearch.2.013259

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Published by the American Physical Society