COULOMB GAP IN A 2-DIMENSIONAL ELECTRON-GAS WITH A CLOSE METALLIC ELECTRODE

The tunneling density of states of a classical two-dimensional electron gas with large external disorder and strong electron-electron interaction is studied by computer modeling and by solving a self-consistent equation. The Coulomb interaction is supposed to be strongly suppressed at large distances by a parallel metallic plane. At low temperatures the Coulomb gap is found to exist even if the metallic plane is at a smaller distance from the electron gas than the electron-electron separation. These results are explained in terms of a self-consistent equation. The tunneling density of states as obtained from computer modeling is compared to recent experimental data by Ashoori et al. For a strong magnetic field our results are in a good agreement with the experiment. © 1995 The American Physical Society.