Quantum Fluctuation Properties of Polariton System in Thermal Vacuum State Field

Using the theory of thermal field dynamics (TFD), a model polariton system is investigated and the squeezing properties of the polariton system at finite temperature is discussed. It is shown that when the photon field is initially in a thermal vacuum state and the phonon initially in its lowest energy level state (the vacuum state), the phonon, photon and also the polariton system can exhibit nonclassical behaviour.