TEMPERATURE-DEPENDENCE OF THE DIELECTRIC-METAL PHASE-TRANSITION IN A 2-DIMENSIONAL SYSTEM OF CHARGE-TRANSFER EXCITONS

The dielectric-metal phase transition at a finite temperature in a two -dimensional system of charge-transfer excitons, which was proposed re cently by Agranovich and Ilinski [Phys. Lett. A 191 (1994) 309], has b een investigated theoretically using pseudospin operators for the mode l Hamiltonian and Weiss molecular field approximation. The numerical r esults show that the phase transition region broadens at low temperatu res, but disappears at high temperatures.