Single-Particle Properties of a Two-Dimensional Fermi Liquid at finite Frequencies and Temperatures

TL;DR

This paper reviews the key frequency, momentum, and temperature dependences of the single-particle self-energy in a two-dimensional Fermi liquid and discusses how these dependences are affected by density, with implications for experimental identification.

Contribution

It provides a detailed analysis of the leading and correction terms of the self-energy in 2D Fermi liquids, highlighting density-dependent limitations for experimental detection.

Findings

Leading dependences are confined to low energy and temperature regions at low densities.

Corrections to these dependences are calculated for the paramagnon model and electron gas.

Implications for experimental identification of Fermi liquid behavior in low-density systems.

Abstract

We review the leading momentum, frequency and temperature dependences of the single particle self-energy and the corresponding term in the entropy of a two dimensional Fermi liquid (FL) with a free particle spectrum. We calculate the corrections to these leading dependences for the paramagnon model and the electron gas and find that the leading dependences are limited to regions of energy and temperature which decrease with decreasing number density of fermions. This can make it difficult to identify the frequency and temperature dependent characteristics of a FL ground state in experimental quantities in low density systems even when complications of band structure and other degrees of freedom are absent. This is an important consideration when the normal state properties of the undoped cuprate superconductors are analyzed.