INTERMEDIATE DIELECTRIC ORDER IN THE ITINERANT ELECTRON-SYSTEMS

The problem about forming the intermediate dielectric order in the system near the phase transition into a long-range order state with the electron-electron correlations and impurity scattering is solved macroscopically. It is shown that for the weak potential of a impurity the formation effect of the intermediate order in its vicinity predominates over the long-range order suppression effect due to the impurity scattering. The effect of intermediate order in the system on the single-particle excitation spectrum and density of states is considered. Since the intermediate order in the system is formed due to the correlation between electron and hole states connected by a continuous class of the inhomogeneity vectors (unlike the long-range order formed by a discrete set of such vectors), the energy scale of changing the density of states is found to be determined by a intermediate value of these vector moduli. Thus in the system having the phase transition into the unhomogeneous state with the inhomogeneity vector modulus q0 the intermediate order forms a pseudogap in the density of states with scale upsilon(F)q0, upsilon(F) being the Fermi velocity This fact differs significantly such a system from the system having a tendency to the phase transition into a homogeneous state (q=0), where the intermediate order forms a upsilon(F)/xi much less than upsilon(F)q0 - scaled pseudogap, xi being the correlation length. A possible role of intermediate dielectric order effects in high temperature superconductors is discussed.