Continuous Quantum Control of Quantum Dot Systems

Sammanfattning: Control and feedback operation of quantum systems have in recent years gained a lot of interest since they are fundamental to achieving functional quantum information processing systems but also of great importance in applications of information to energy conversion within quantum thermodynamics. This thesis has treated a new formalism for feedback control of quantum systems. This formalism is able to analytically describe non-linear feedback protocols, something that was previously described by stochastic equations, only solvable numerically. This new formalism was applied to two test systems, one classical system as well as one quantum system consisting of double dots. These systems were studied using both analytical and full numerical solutions. It was found that by using non-linear feedback schemes both these systems could be operated as information engines.