Observation of a Non-Ohmic Hall Resistivity at Low Temperatures in a Two-Dimensional Electron Gas

Hall measurements of electron inversion layers at low temperatures and electric fields are reported. For resistances of {} 10 k{Ω}/{} a logarithmic dependence of the Hall coefficient on temperature and Hall voltage is observed. This indicates that the logarithmic dependences observed for the resistance of metal films and metal-oxide-semiconductor field-effect transistors are not evidence for the scaling theory of localization. These results are also difficult to resolve within the theory of interaction effects by Altshuler, Aronov, and Lee.