Spectral properties of the planar t-J model

TL;DR

This paper investigates the spectral functions and self-energies of the planar t-J model, revealing asymmetries between electron and hole spectra and aligning with experimental observations in cuprates.

Contribution

It provides a detailed analysis of spectral asymmetries in the t-J model using finite-temperature Lanczos calculations, highlighting the marginal Fermi liquid behavior for holes.

Findings

Hole spectra are overdamped with Im Σ ∝ ω, consistent with marginal Fermi liquid theory.

Electron quasiparticles exhibit weak damping, indicating asymmetry in spectral properties.

Results agree with experimental data on cuprate superconductors.

Abstract

The single-particle spectral functions $A({\bf k},\omega)$ and self-energies $\Sigma({\bf k},\omega)$ are calculated within the $t-J$ model using the finite-temperature Lanczos method for small systems. A remarkable asymmetry between the electron and hole part is found. The hole (photoemission) spectra are overdamped, with ${\rm Im} \Sigma \propto \omega$ in a wide energy range, consistent with the marginal Fermi liquid scenario, and in good agreement with experiments on cuprates. In contrast, the quasiparticles in the electron part of the spectrum show weak damping.