Pseudogap and photoemission spectra in the attractive Hubbard model

TL;DR

This paper investigates the pseudogap phenomenon in the two-dimensional attractive Hubbard model using microscopic calculations of photoemission spectra, revealing temperature-dependent suppression of spectral weight at the chemical potential.

Contribution

It provides a detailed numerical analysis of the spectral function showing pseudogap behavior and its temperature dependence, aligning with experimental observations in cuprates.

Findings

Spectral function exhibits a two-peak structure due to bound states.

Pseudogap suppression occurs at the chemical potential.

Pseudogap diminishes and disappears at high temperatures.

Abstract

Angle-resolved photoemission spectra are calculated microscopically for the two-dimensional attractive Hubbard model. A system of self-consistent T-matrix equations are solved numerically in the real-time domain. The single-particle spectral function has a two-peak structure resulting from the presense of bound states. The spectral function is suppressed at the chemical potential, leading to a pseudogap-like behavior. At high temperatures and densities the pseudogap diminishes and finally disappears; these findings are similar to experimental observations for the cuprates.