Speaker
Description
It is investigated whether the non-Markovianity, i.e., the memory effects resulting from the coupling of the system to its environment, can be beneficial for the performance of quantum heat engines. Specifically, a version of a single-qubit Otto engine is studied in which the standard thermalization strokes are replaced with so-called extremal thermal operations, which cannot be realized without the memory effects [1]. The performance of such a device is compared with both the Markovian (memoryless) Otto engine and the three-stroke engine studied by Łobejko et al. [2], in which the cycle consists of two extremal thermal operations and a single qubit rotation. It is first demonstrated that the non-Markovian Otto engine can generate more work per cycle for a given efficiency than its Markovian counterpart, which, on the other hand, exceeds the performance of the three-stroke engine. Secondly, the ratio of the work fluctuations to the mean work is analyzed. It is shown that both the non-Markovian Otto engine and the three-stroke engine produce less work fluctuations than the Markovian setup (thus providing a more stable operation), whereas their relative performance depends on the target efficiency and work-per-cycle. This leads to the conclusion that the non-Markovian effects can improve the performance of quantum heat engines.
References
[1] E. A. Aguilar, H. Wojewódka-Ściążko, M. Stankiewicz, C. Perry, P. Ćwikliński, A. Grudka, K. Horodecki, and M. Horodecki, arXiv:2009.03110 (2020).
[2] M. Łobejko, P. Mazurek, and M. Horodecki, Quantum 4, 375 (2020).
