The so-called two dimensional metal-insulator transition

TL;DR

This paper critically examines the phenomena and physical mechanisms behind the two-dimensional metal-insulator transition in low-density semiconductor systems, emphasizing the role of long-range Coulomb disorder from charged impurities.

Contribution

It offers a critical perspective on the low-temperature transport phenomena and highlights the importance of Coulombic disorder in understanding the 2D MIT.

Findings

Long-range Coulomb disorder is a key factor in 2D MIT behavior.

The anomalous metallic phase is influenced by impurity-induced disorder.

Transport phenomena are critically linked to impurity distribution in 2D systems.

Abstract

We provide a critical perspective on the collection of low-temperature transport phenomena in low-density two-dimensional semiconductor systems often referred to as the 2D metal-insulator transition. We discuss the physical mechanisms underlying the anomalous behavior of the two-dimensional effective metallic phase and the metal-insulator transition itself. We argue that a key feature of the 2D MIT physics is the long-range bare Coulombic disorder arising from the random distribution of charged impurities in the low-density 2D semiconductor structures.