Kinematic formation of the pseudogap spectral properties in a spatially homogeneous strongly correlated electron system

TL;DR

This paper demonstrates that kinematic interactions in a strongly correlated electron system can induce pseudogap behavior in spectral properties, aligning well with experimental ARPES data on cuprates.

Contribution

It reveals that kinematic interactions modify the Green's function of Hubbard fermions, leading to pseudogap features and spectral weight modulation, supported by calculations matching experimental data.

Findings

Kinematic interactions induce pseudogap behavior.

Spectral intensity modulates on the Fermi contour.

Calculated spectral properties agree with ARPES data.

Abstract

It is shown that the kinematic interaction caused by the quasi-Fermi character of commutation relations for operators of the atomic representation can induce pseudogap behavior of the spectral characteristics of an ensemble of Hubbard fermions. Mathematically, the presence of the kinematic interaction manifests itself in modification of the faithful representation of a single-particle Green's function of Hubbard fermions $D(\textbf{k},i\omega_n)$, which involves, apart from self-energy operator $\Sigma_L(\textbf{k},i\omega_n)$, strength operator $P(\textbf{k},i\omega_n)$. It is important that the strength operator enters both the numerator and the denominator of the exact expression for $D(\textbf{k},i\omega_n)$. The kinematic interaction, therefore, not only renormalizes the spectrum of elementary excitations but significantly affects their spectral weight. It results in strong modulation of spectral intensity $A(\textbf{k},\omega)$ occurring on a Fermi contour. Calculations of the spectral properties for the $t-J$ model in the one-loop approximation yield good quantitative agreement with the ARPES data obtained on cuprate superconductors.