Quantum transport experiments of Si-MOS inversion layers have been done at temperatures between 50 mK and 1.45 K and in magnetic fields between 14 and 23 T using samples having two grades of electron mobility. The Hall conductivity were analyzed employing a model calculation to derive the temperature dependence and the magnetic field dependence of the mobility edge. At low temperatures, the mobility edge was independent of temperature and independent of magnetic field suggesting the mobility edge is dominated by a macroscopic potential fluctuations. The temperature dependence of the mobility edge at high temperatures can not be explained by the existing theory of localization in Landau subbands in two dimensional systems and that of the temperature dependence of the inelastic scattering in the zero magnetic field.
ASJC Scopus subject areas
- Physics and Astronomy(all)