Wigner solid or Anderson solid -- 2D electrons in strong disorder

TL;DR

This paper critically examines recent experimental claims of a Wigner solid in disordered 2D electron systems, arguing that the observed phase is better described as an Anderson solid characterized by impurity-induced localization rather than a crystal formed by electron interactions.

Contribution

The paper provides a theoretical reinterpretation of experimental data, proposing that the low-density phase is an Anderson solid rather than a Wigner crystal, emphasizing the role of disorder-induced localization.

Findings

The observed phase is amorphous and localized by impurities.

The phase is connected to the infinite disorder Anderson fixed point.

It is distinct from the interaction-driven Wigner crystal.

Abstract

Critically analyzing recent STM and transport experiments [Z. Ge, et al, arXiv:2510.12009] on 2D electron systems in the presence of random quenched impurities, we argue that the resulting low-density putative "solid" phase reported experimentally is better described as an Anderson solid with the carriers randomly spatially localized by impurities than as a Wigner solid where the carriers form a crystal due to an interaction-induced spontaneous breaking of the translational symmetry. In strongly disordered systems, the resulting solid is amorphous, which is adiabatically connected to the infinite disorder Anderson fixed point rather than the zero disorder Wigner crystal fixed point.