Abstract:

Driven-dissipative systems in two dimensions can differ substantially from their equilibrium counterparts. Particularly, quantum fluids of light, such as exciton-polaritons in microcavities, constitute paradigmatic cases of non-equilibirum physics. These quantum systems, which appear as a consequence of the hybridization between light and excitons, are not isolated due to the existence of i) an external pumping laser that maintains a finite density of polaritons ii) a non-zero dissipation due to the leaking of cavity photons through the mirrors. The subtle interplay between the external drive and the cavity losses may drive the system to exotic and genuinely non-equilibrium phases. Moreover, demonstrations of polariton lattices in semiconductor microcavities, in combination with their extraordinary non-linear properties, place these quantum-fluids of light as one of the most promising candidates to achieve quantum simulation in compact on-chip scalable platforms. In this lecture I will give an introduction to the physics of quantum fluids of light and the different techniques in order to study the static and dynamical properties of such non-equilibrium systems. I will review the state of the art of this particular field and will mention different open questions and future research topics concerning microcavity polaritons and non-equilibrium systems.