PT-symmetry effects in measurement-based quantum thermal machines

Measurement-based quantum thermal machines are fascinating models of thermodynamic cycles where measurement protocols play an important role in the performance and functioning of the cycle. Despite theoretical advances, interesting experimental implementations have been reported. Here we move a step further by considering a measurement-based quantum thermal machine model where the only thermal bath is structured with PT-symmetric non-Hermitian Hamiltonians. Theoretical results indicate that PT-symmetric effects and measurement protocols are related along the cycle. Furthermore, tuning the parameters suitably it is possible to improve the absorbed heat and the extracted work, operating in the Otto limit for the efficiency, provided we consider a quasistatic cycle. Our model also allows switching the configuration of the cycle, engine, or refrigerator, depending on the strength of the measurement protocol.