Destruction of Strong Critical Spin Fluctuations by Doping in the 2D Hubbard Model

TL;DR

This study investigates how doping affects spin fluctuations and electronic properties in the 2D Hubbard model, revealing that doping suppresses critical spin fluctuations and restores Fermi liquid behavior.

Contribution

It provides a detailed analysis of doping effects on spectral functions and self-energy, demonstrating the destruction of critical spin fluctuations at specific doping levels.

Findings

Critical spin fluctuations are destroyed at 13% doping for U=4 and 20% for U=8.

Below these doping levels, the self-energy exhibits quadratic frequency dependence, indicating Fermi liquid behavior.

Doping modifies spectral functions and density of states significantly.

Abstract

We present the doping dependence of the spectral functions, density of states and low frequency behavior of the self-energy for the 2D Hubbard model on the basis of our recently developed theory for the Hubbard model. Strong 2D critical spin fluctuations dominating near half-filling are completely destroyed by 13 and 20 percent doping concentrations for U=4 and 8, respectively. Below these concentrations the imaginary part of the self-energy vanishes quadratically in frequency near the Fermi energy, a characteristic feature for the Fermi liquid.