• quantum mechanics
• open systems
• optimal control

In this thesis we investigate the controlled (coherent, i.e. without feedback from measurements) dynamics of a dissipative two-level quantum system subject to Generalized Amplitude Damping in the Markovian approximation. Our goal is to accelerate the relaxation of the system, starting from a state ``more pure'' than the fixed point. Roughly speaking, we want to speed up the heating of the system, when its initial state is colder than the bath. This problem may be of fundamental importance in quantum information and computation , where the two-level system play plays the role of qubit, the basic unit of information in quantum computation.