abstract:

Exciton polaritons in two-dimensional semiconductors inside microcavities are powerful platformsto explore hybrid light-matter quantum systems. Here, we study the Bose-Einstein condensationof polaron-polaritons, which are quasiparticles formed by the dressing of exciton polaritons byparticle-hole excitations in a surrounding electron gas. Using a non-perturbative many-body theoryto describe exciton-electron correlations combined with a non-equilibrium theory for the condensate,we show that the electrons strongly affect the condensate. This stems from the dependence of thepolaron-polariton energy and the interaction between them on the electron density, which leads tohighly nonlinear effects. We identify stable and unstable regimes of the condensate by calculatingits excitation spectrum, and show that they result in prominent hysteresis effects when the electrondensity is varied. Our results should be readily observable using present experimental technology.