Correlations weak and strong: divers guises of the two-dimensional electron gas

TL;DR

This paper explores the diverse behaviors of the two-dimensional electron gas, highlighting its significance in understanding strongly correlated electronic states in quantum wells and related experimental observations.

Contribution

It provides a comprehensive discussion of the various correlation effects in 2D electron systems and their experimental manifestations, emphasizing the model's relevance beyond the 3D case.

Findings

Correlations in 2D electron gases can be both weak and strong.

Quantum wells exhibit diverse many-particle states due to 2D correlations.

Tunneling spectroscopy reveals signatures of these correlation effects.

Abstract

The three-dimensional electron-gas model has been a major focus for many-body theory applied to the electronic properties of metals and semiconductors. Because the model neglects band effects, whereas electronic systems are generally more strongly correlated in narrow band systems, it is most widely used to describe the qualitative physics of weakly correlated metals with unambiguous Fermi liquid properties. The model is more interesting in two space dimensions because it provides a quantitative description of electrons in quantum wells and because these can form strongly correlated many-particle states. We illustrate the range of possible many-particle behaviors by discussing the way correlations are manifested in 2D tunneling spectroscopy experiments.