Surprising coincidence of the apparent 2D metal-to-insulator transition data with Fermi-gas based model results

TL;DR

This paper reveals an error in the melting condition for 2D Wigner solids and shows that experimental data for 2D metal-insulator transitions align with Fermi-gas model predictions, challenging previous assumptions about Wigner solidification.

Contribution

It corrects a fundamental error in the melting condition of 2D Wigner solids and demonstrates that observed 2D metal-insulator transition data can be explained without Wigner solidification, using a Fermi gas model.

Findings

The melting condition for 2D Wigner solid contains a factor of π error.

Experimental data do not support Wigner solidification in 2D systems.

Fermi gas model explains metallic and insulating behaviors across densities and temperatures.

Abstract

The melting condition for two-dimensional Wigner solid ( P.M. Platzman, H.Fukuyama, 1974) is shown to contain an error of a factor of $\pi$. The analysis of experimental data for apparent 2D metal-to-insulator transition shows that the Wigner solidification (B.Tanatar, D.M.Ceperley, 1989) has been never achieved. Within routine Fermi gas model both the metallic and insulating behavior of different 2D system for actual range of carrier densities and temperatures is explained.