Quantum optics deals with the quantum nature of light and its interaction with matter. Substantial experimental progress has been made in this field during the last thirty years, including demonstrations of quantum entanglement, squeezed states and single photon emitters. Quantum optical systems are also central to various attempts to realise quantum information processing devices. This
project will contribute to the theoretical understanding and analysis of experiments in quantum optics. In particular, i t will focus on two types of systems. The first type are systems within the circuit QED paradigm, where electrical circuits and microwave photons are utilised in the effort to realise quantum computers. This route has reached a number of milestones in rec ent years, such as single photon generation on demand and transfer of quantum information from one qubit to another. In the
future, when increasing the number of qubits, important goals will be to demonstrate multiparticle entanglement and quantum error c orrection. The project will face the theoretical challenge of describing the dynamics and entanglement in such complicated quantum multiparticle systems. The second type are optomechanical systems, where the coupling of the electromagnetic field to macros copic mechanical elements can display quantum effects. These systems provide a new and exciting arena for studying the connection between quantum and classical physics. They offer the possibility of laser cooling a macroscopic mechanical element to its qu antum ground state and observing its dynamics through quantum nondemolition measurements. The project will
contribute to the planning and analysis of such experiments. Research on these types of systems can be of technological importance in fields like qu antum computation, spectroscopy and precision metrology. In addition, they enforce the development of a more profound understanding of quantum physics.