Generation of multipartite entanglement in coupled-cavity arrays as a resource for quantum technologies

Abstract

Entanglement is an essential part of quantum mechanics and a resource for most quantum technologies. While entangled two-particle Bell states are well established, the generation and classification of entanglement in multipartite systems is much more difficult to achieve. At the same time, multipartite entanglement is the key to unlock the full advantage provided by the exponentially large Hilbert space of quantum systems. This thesis explores possibilities of entanglement generation with a specific focus on applications in quantum technologies. In systems of coupled microcavity arrays, coherent optical pulses are considered to directly drive the quantum system into multipartite entangled target states. The building block of such coupled-cavity arrays consists of a single mode cavity with a two-level emitter, whose interaction is described by the Jaynes–Cummings model. In order to gain insight into the system, a novel representation of its eigenspectrum is presented, which shows the eigenenergies and the composition of the corresponding eigenstates. Based on this, a numerical scheme, which is the central achievement of this thesis, is developed that allows to determine precise excitation parameters to generate entanglement. Finally, this scheme is used to show the generation of multipartite entanglement in the form of W and phased Dicke states with high fidelity.