Quantum engine based on general measurements

In this work, we introduce a three-stroke quantum engine with a single-qubit work-ing substance whose cycle consists of two strokes arise due to performing two distinctgeneral quantum measurements and it is completed by thermalization through contactwith a finite temperature thermal reservoir. It is demonstrated that energy is importedinto the engine by first measurement channel and work (usefulenergy) is extracted fromit, in a frictionless isentropic manner, by the second measurement channel. It is par-ticularly shown that the engine is capable to have perfect efficiency. In continuation,we equip the the engine cycle with two additional adiabatic strokes. As illustrated,the presence of adiabatic strokes in the cycle provide an improved lower bound for theparametrized efficiency range of the engine.