Maximal power for heat engines: role of asymmetric time switchings

The performance of endoreversible thermal machines operating at finite power constitutes one of the main challenges of nonequilibrium classical and quantum thermodynamics, engineering and others. Here we address the role of a so far unexplored (but very realistic) ingredient: asymmetric interaction times between system and reservoirs. We consider one of the simplest thermal ma chines, composed of a quantum dot interacting sequentially with two different reservoirs of heat and particles. Distinct optimization protocols are analyzed in the framework of stochastic thermodynamics. Results reveal that asymmetric time switchings plays a fundamental role in enhancing the power output and that maximizations can provide efficiencies at maximum power greater than the endoreversible Curzon-Ahlborn efficiency for a broad range of revervoir temperatures.