THE METAL-INSULATOR PHASE-TRANSITION, QUASI-PARTICLE DAMPING AND SUPERCONDUCTIVITY IN A LAYERED FERMI GAS

By means of the Fermi-liquid approach, the effects of exchange and cor relations are considered in a layered two-dimensional electron gas. A graphical derivative technique is introduced to obtain the contributio ns to the interparticle interactions from different channels. It is sh own that the interaction in the particle-hole channel can induce the m etal-insulator phase transition when the Fermi momentum is comparable with the inverse interlayer spacing, p(F) approximate to 1/c. It is al so shown that the Cooper-like scattering processes give rise to the sc aling of the Fermi liquid response as chi similar to omega/T, which le ads to the linear temperature dependence of the quasiparticle damping. The possibility of superconductivity in the region between the insula tor and normal metal phases, accounting for the particle-hole excitati ons, is discussed. The effect of the spin fluctuations on the supercon ductivity due to the particle-hole excitations is also considered.