COULOMB GAP AND TRANSPORT IN CLASSICAL ELECTRON LIQUID

The lattice model of a classical electron liquid with the Coulomb interaction and zero kinetic energy is considered. It is shown by both qualitative arguments and computer modeling that in this system the Coulomb gap exists near the chemical potential. Arguments are given that this is true for the nonideal quantum liquid as well. Nearest-neighbor hopping conductivity is studied at d = 2. At low temperatures, the conductivity mechanism is shown to be a many-electron diffusion. At very small external disorder, the crossover from the diffusion to percolation has been found.