SAMOP 2023 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 8: QI Poster I (joint session QI/Q)

Q 8.15: Poster

Monday, March 6, 2023, 16:30–19:00, Empore Lichthof

Engineering a heat engine purely driven by quantum coherence — •Stefan Aimet — Imperial College London, London, United Kingdom — FU Berlin, Berlin, Germany

The question of whether quantum coherence is a resource beneficial or detrimental to the performance of quantum heat engines has been thoroughly studied but remains undecided. To isolate the contribution of coherence, we analyse the performance of a purely coherence-driven quantum heat engine, a device that does not include any heat flow during the thermodynamic cycle. The engine is powered by the coherence of a multi-qubit system, where each qubit is charged via interaction with a coherence bath using the Jaynes-Cummings model. We demonstrate that optimal coherence charging and hence extractable work is achieved when the coherence bath has an intermediate degree of coherence. In our model, the exctractable work is maximised when four copies of the charged qubits are used. Meanwhile, the efficiency of the engine, given by the extractable work per input coherence flow, is optimised by avoiding coherence being stored in the system-bath correlations that is inaccessible to work. We numerically find that the highest efficiency is obtained for slightly lower temperatures and weaker system-bath coupling than those for optimal coherence charging.