On the Theory of Metal-Insulator Transitions in Gated Semiconductors

TL;DR

This paper presents a simple model explaining 2D metal-insulator transitions in gated semiconductors through charged trap scattering, accounting for resistivity changes, temperature dependence, and field effects.

Contribution

It introduces a model linking resistivity to charged trap occupation, providing a unified explanation for experimental observations of the transition.

Findings

Resistivity is controlled by scattering at charged traps.

Temperature dependence of resistivity arises from trap occupation.

Model explains scaling and field effects observed experimentally.

Abstract

It is shown that recent experiments indicating a metal-insulator transition in 2D electron systems can be interpreted in terms of a simple model, in which the resistivity is controlled by scattering at charged hole traps located in the oxide layer. The gate voltage changes the number of charged traps which results in a sharp change in the resistivity. The observed exponential temperature dependence of the resistivity in the metallic phase of the transition follows from the temperature dependence of the trap occupation number. The model naturally describes the experimentally observed scaling properties of the transition and effects of magnetic and electric fields.