Properties of the Two-Dimensional Electron Gas Close to the Fermi-Liquid Quantum Critical Point

TL;DR

This paper investigates the behavior of a two-dimensional electron gas near a quantum critical point, revealing phase transitions and non-Fermi-liquid behavior through a microscopic analysis.

Contribution

It provides a detailed microscopic description of quasiparticle spectrum rearrangements and phase transitions near the quantum critical point in a 2D electron gas.

Findings

Emergence of multi-connected quasiparticle momentum distribution at low temperatures

Identification of two temperature-induced crossovers involving fermion condensates

Prediction of four distinct quasiparticle phases near the critical point

Abstract

The rearrangement of single-particle degrees of freedom of a dilute two-dimensional electron gas in the vicinity of the quantum critical point is examined within a microscopic approach. It is shown that just beyond the critical point, the Landau state undergoes self-consistent rearrangement of the quasiparticle spectrum and momentum distribution. At very low temperatures, there emerges a multi-connected quasiparticle momentum distribution. With increasing temperature, two crossovers occur: a fermion condensate appears in the first and disappears in the second, giving way to universal non-Fermi-liquid behavior. Manifestations of these crossovers in thermodynamic properties of the electron gas are studied and characterized. The four quasiparticle phases predicted to exist in the vicinity of the critical point are collected in a schematic phase diagram.