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Frequency dependence of the inversion layer conductivity in the metallic and localized regimes
Surface Science 58 (1976) 17 0 North-Holland Publishing Company
FREQUENCY
DEPENDENCE OF THE INVERSION
CONDUCTIVITY
LAYER
IN THE METALLIC AND LOCALIZED
REGIMES
S.J. ALLEN, Jr., D.C. TSUI and F. DeROSA Bell Laboratories, Murray Hill, New Jersey 07974,
USA
The conductivity of electrons in the inversion layer of silicon has been measured from 0 to 40 cm-l at 1.2 K at electron concentrations, ns, spanning the metallic and localized regimes. a(w) is Drude like at metallic densities and at localized densities for Biw > EA, when EA is the thermal activation energy measured from o(l/T). Extrapolating the Drude like behavior in the localized regime back to w = 0 gives 00, the prefactor for the thermally activated behavior. These results can be explained by the appearance of a gap at fermi level. They are not consistent with classical percolation or near neighbor hopping, or a mobility edge, E,, fixed by potential fluctuations unless E, is a strong function of n,.
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FREQUENCY
DEPENDENCE OF THE INVERSION
CONDUCTIVITY
LAYER
IN THE METALLIC AND LOCALIZED
REGIMES
S.J. ALLEN, Jr., D.C. TSUI and F. DeROSA Bell Laboratories, Murray Hill, New Jersey 07974,
USA
The conductivity of electrons in the inversion layer of silicon has been measured from 0 to 40 cm-l at 1.2 K at electron concentrations, ns, spanning the metallic and localized regimes. a(w) is Drude like at metallic densities and at localized densities for Biw > EA, when EA is the thermal activation energy measured from o(l/T). Extrapolating the Drude like behavior in the localized regime back to w = 0 gives 00, the prefactor for the thermally activated behavior. These results can be explained by the appearance of a gap at fermi level. They are not consistent with classical percolation or near neighbor hopping, or a mobility edge, E,, fixed by potential fluctuations unless E, is a strong function of n,.
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