Spontaneous coherence within a gas of exciton-polaritons in Telluride microcavities

Abstract

Microcavity exciton-polaritons are the eigenstates resulting from strong light-matter coupling in high quality monolithic semiconductor microcavities. Owing to their mixed photonic and excitonic nature, polaritons are Bose particles of very light mass and short lifetime that can interact with their environment, forming a new class of Bose gas. In spite of their short lifetime, a polariton gas can show Bose-Einstein condensation or polariton lasing depending on the experimental conditions. The properties of these coherent states of polaritons are unique in many respects. In this chapter we rely on a comprehensive set of experimental and theoretical works carried out this last decade to give a detailed description of polariton coherent states. The influences of finite lifetime, disorder and interaction with the environment are addressed, and the analogies and differences between polariton condensate, polariton lasing, equilibrium Bose gas and photon lasing are outlined and discussed.