Physics of excitonic quasiparticles: beyond conventional polaritons

Some aspects of post-conventional polariton physics are discussed. In the framework of quantum statistical properties we demonstrate that polaritons are intrinsically squeezed. The polariton squeezing is frequency tunable, and can be larger than that in usual atomic systems. The new phonoriton excitation, which gives rise to spectrum reconstruction, is reexamined on the basis of a simple model: threshold behavior, new gap structure and related properties are discussed.