Abstract
The tunneling-current anomaly in Au/p-GaAs0.94Sb0.06 contacts at zero bias voltage (V) → 0) is investigated. Epitaxial layers of the solid solution GaAs0.94Sb0.06 are doped with germanium and have a conductivity close to that at the metal-insulator transition. The square-root dependence of the differential conductance G(V)=(dV/dI)−1 at small values of eV>kT TT predicted by the Al’tshuler-Aronov theory of quantum corrections to the density of states at the Fermi level in disordered conductors is observed. Satisfactory agreement between the experimental data and theory is observed at hole densities (p) in the layers greater than the critical density for the metal-insulator transition p c , but the relative magnitude of the anomaly is sharply smaller at p<p c . This confirms the specificity of the condition k F l⩾1 (instead of
) for applicability of the theory for the density-of-states anomaly appearing as a result of electron-electron interactions in a three dimensional electron gas.
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Fiz. Tekh. Poluprovodn. 32, 1424–1431 (December 1998)
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Allen, T.Y., Nazhmudinov, K.G. & Polyanskaya, T.A. Density-of-states anomaly and tunneling conductance of Au/p-GaAs0.94Sb0.06 contacts near the metal-insulator transition. Semiconductors 32, 1270–1276 (1998). https://doi.org/10.1134/1.1187613
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DOI: https://doi.org/10.1134/1.1187613