Colored noise in Open Quantum Systems: Noisy frequency estimation and control methods

Abstract

The dynamics of any quantum device is altered by its interaction with the surrounding environment. This thesis discusses the impact of noise in a scenario of quantum frequency estimation and techniques to control the dynamics between interacting quantum systems, as well as a method to tailor memory effects in the dynamics of an experimentally relevant system. In particular, we exploit a quantum metrology setting where N two level systems are employed as probes to estimate the amplitude of a field which alters their level splitting in a linear fashion. There, we explore the fundamental limits of the estimation precision we can achieve using quantum strategies. Furthermore, we apply newly developed quantum control methods to nitrogen-vacancy centers in diamond. These techniques are focused on the interpretation of frequency spectra, the creation of high fidelity two-qubit gates via specifically designed dynamical decoupling sequences and the control of memory effects in the open quantum system dynamics of the nitrogen-vacancy center.