Impact of the sequence of system-environment interactions on the functionality and efficiency of quantum thermal machines

In this work, we investigate effects of the sequence of system-environment interactions on the functionality and performance of quantum thermal machines (QTMs). The working substance of our setup consists of two subsystems, each independently coupled to its local thermal reservoir and further interconnected with a common reservoir in a cascaded manner. We demonstrate the impact of the sequential interactions between the subsystems and the common reservoir by exchanging the temperatures of the two local reservoirs. Our findings reveal that, when the two subsystems are in resonance, such an exchange alters the efficiency of QTMs without changing their functional types. Conversely, when the two subsystems are detuned, this exchange not only changes the efficiency but also the types of QTMs. Our results indicate that the manners of system-reservoir interactions offer significant potential for designing QTMs with tailored functionalities and enhanced performance.