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

## TL;DR

This paper shows how the order of system-environment interactions affects the performance and function of quantum thermal machines.

## Contribution

The novelty lies in demonstrating how swapping reservoir temperatures alters QTM efficiency and functionality based on subsystem resonance or detuning.

## Key findings

- Resonant subsystems maintain functionality but change efficiency when reservoir temperatures are swapped.
- Detuned subsystems experience changes in both efficiency and functionality with reservoir temperature exchange.
- System-reservoir interaction sequences offer potential for designing tailored and efficient QTMs.

## Abstract

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.