Polariton Condensates in Low Dimensional Cavities

In the past few years, semiconductor microcavities have appeared to be a very attractive system for the exploration of the physics of interacting Bose condensates. In addition to the flexibility and richness of optical experiments that can be performed on polariton condensates in microcavities, the powerful tools offered by technological processes developed for opto-electronic devices can be used to fully engineer the potential landscape in which these half-light half-matter condensates evolve. In the present chapter, we will describe how polariton condensates can be confined in low dimensional microstructures. We will review some experiments performed in these geometries, highlighting the huge potential of microstructures for the development of innovative polaritonic devices. We will first address experiments performed in wire cavities, which open the field of mesoscopic physics with polaritons. Propagation of polariton condensates over macroscopic distances has been demonstrated as well as the optical manipulation of these condensates (tunnel coupling and trapping). We will also discuss scattering by disorder in this one dimensional propagation. Then we will describe experiments in fully confined systems like single or coupled micropillars. These 0D resonators allow proper investigation of the nature of interactions undergone by polariton condensates. To conclude we will mention several theoretical proposals which make use of the propagation and manipulation of polariton condensates in photonic circuits to develop new optical functionalities and reveal new physics.