Single-Particle Pseudogap in Two-Dimensional Electron Systems

TL;DR

This paper models the pseudogap phenomena in two-dimensional electron systems, especially cuprates, using mode-mode coupling theory to analyze single-particle dynamics and reproduce experimental observations.

Contribution

It introduces a theoretical framework combining AFM and $d_{x^2-y^2}$-wave superconducting fluctuations to explain pseudogap behavior in 2D electron systems.

Findings

Pseudogap structure appears below $ ext{T}_{PG}$ in underdoped cuprates.

Model reproduces absence of pseudogap in overdoped cuprates.

Results align qualitatively with experimental data.

Abstract

We investigate pseudogap phenomena in the 2D electron system. Based on the mode-mode coupling theory of antiferromagnetic (AFM) and $d_{x^2-y^2}$-wave superconducting ($d$SC) fluctuations, single-particle dynamics is analyzed. For the parameter values of underdoped cuprates, pseudogap structure grows in the single-particle spectral weight $A(k,\omega)$ around the wave vector $(\pi,0)$ and $(0,\pi)$ below the pseudo-spin-gap temperature $\TPG$ signaled by the reduction of dynamical spin correlations in qualitative agreement with the experimental data. The calculated results for the overdoped cuprates also reproduce the absence of the pseudogap in the experiments. We also discuss limitations of our weak-coupling approach.