D. Simonian

Electric Field Scaling at a {ital B={bold 0}} Metal-Insulator Transition in Two Dimensions

The nonlinear (electric field-dependent) resistivity of the 2D electron system in silicon exhibits scaling as a function of electric field and electron density in both the metallic and insulating phases, providing further evidence for a true metal-insulator transition in this 2D system at {ital B}=0. Comparison with the temperature scaling yields separate determinations of the correlation length exponent, {nu}{approx_equal}1.5, and the dynamical exponent, {ital z}{approx_equal}0.8, close to the theoretical value {ital z}=1. {copyright} {ital 1996 The American Physical Society.}

Comment on “Theory of metal-insulator transitions in gated semiconductors”

A Comment on the Letter by Boris L. Altshuler and Dmitrii L. Maslov, Phys.thinspthinspRev.thinspthinspLett.thinspthinsp{bold 82}, 145 (1999). The authors of the Letter offer a Reply. {copyright} {ital 1999} {ital The American Physical Society}In a recent Letter, Altshuler and Maslov propose a model which attributes the anomalous temperature and field dependence of the resistivity of two-dimensional electron (or hole) systems to the charging and discharging of traps in the oxide (spacer), rather than to intrinsic behavior of interacting particles associated with a conductor-insulator transition in two dimensions. We argue against this model based on existing experimental evidence.

Metal-insulator transition in Si:{bold {ital X}} ({bold {ital X}}=P,B): Anomalous response to a magnetic field

The zero-temperature magnetoconductivity of just-metallic Si:P scales with magnetic field, H, and dopant concentration, n, lying on a single universal curve. We note that Si:P, Si:B, and Si:As all have unusually large magnetic field crossover exponents near 2, and suggest that this anomalously weak response to a magnetic field is a common feature of uncompensated doped semiconductors.

The metal-insulator transition in Si:X: Anomalous response to a magnetic field

The zero-temperature magnetoconductivity of just-metallic Si:P scales with magnetic field, H, and dopant concentration, n, lying on a single universal curve. We note that Si:P, Si:B, and Si:As all have unusually large magnetic field crossover exponents near 2, and suggest that this anomalously weak response to a magnetic field is a common feature of uncompensated doped semiconductors.