Irreversible quantum thermodynamic processes and quantum heat engines

This thesis is devoted to quantum thermodynamics where I examine the extension of the laws, processes, and cycles of thermodynamics to quantum mechanical systems. I show that, for example, the zeroth law of thermodynamics cannot be directly extended to the quantum domain due to the lack of a temperature operator. Specifically, the Carnot and Otto cycles are extended for a general quantum system. The implications of quantum mechanics on the construction of a reversible Carnot cycle are revealed. Full quantum mechanical cycle description and the quantum formulation of the second law are given for the irreversible Carnot cycle.