"Both electrons and photons have emerged as essential particles in our information age. Electrons interact strongly with each other and form the basis for computational architectures, while photons interact weakly and are the ideal candidates for communication. While the strength of each particle can also be viewed as a weakness, an emerging research field has focused on the fundamental physics of hybrid particles between electrons and photons. Known as exciton-polaritons, such particles can be generated in solid-state nanostructures such as semiconductor microcavites. Naturally, exciton-polaritons exhibit a mix of properties of electrons and photons and recent fundamental studies have revealed their Bose-Einstein condensation, superfluidity and a rich spin dynamics.With a range of basic physical effects now known, the potential for constructing devices from these hybrid particles has appeared, yet remains largely unstudied. Optical or electrical spin control of exciton-polaritons has a perspective for information processing, where the strong non-linear interactions between excitons could be sufficient for a complete logical functionality. Going beyond classical effects, exciton-polaritons are quantum particles and seem to be realistic candidates for quantum information processing. Unfortunately the field of exciton-polariton physics has evolved rather separately from the field of quantum information science, likely due to the difficulty in applying the most basic ideas of quantum information theory to exciton-polaritons. Namely, it is not known how to isolate exciton-polaritons as qubits (since they are bosons) such that more advanced schemes based on continuous variables are required.The aim of this project is to design and study theoretically exciton-polariton based devices. To understand the promise and limitations of these particles an interdisciplinary project between condensed matter physics, quantum optics and quantum information theory is essential."