Using non-Markovian dynamics in effective-negative-temperature-based transient quantum Otto engines

Conventional quantum Otto engines based on effective-negative-temperature reservoirs rely on an assumption of perfect thermalization. In this study, the authors investigate the impact of non-Markovianity in these engines by terminating strokes before reaching thermal equilibrium, revealing that higher non-Markovianity enhances maximum efficiency but reduces overall performance over an extended period of functioning time. The authors also identify a class of effective-negative-temperature-based necessarily transient quantum Otto engines.