A possible role of D^- band in hopping conductivity and metal-insulator transition in 2D structures

TL;DR

This paper proposes a two-band model where the D^- band dominates conductivity, explaining unusual hopping magnetoresistance and metal-insulator transition features in 2D structures, supported by experimental evidence.

Contribution

It introduces a simple two-band model emphasizing the D^- band role in 2D hopping conductivity and metal-insulator transition, supported by experimental data.

Findings

D^- band dominates conductivity in the model

Experimental data supports the model's validity

Explains unusual magnetoresistance features

Abstract

A simple two-band model is suggested explaining recently reported unusual features for hopping magnetoresistance and the metal-insulator transition in 2D structures. The model implies that the conductivity is dominated by the upper Hubbard band (D^- band). Experimental studies of hopping magnetoresistance for Si delta doped GaAs/AlGaAs heterostructure give additional evidences for the model.