Role of strong correlation in the recent ARPES experiments for cuprate superconductors

TL;DR

This study numerically investigates low-lying excitations in strongly correlated cuprate superconductors, revealing linear momentum dependence along the nodal direction and matching experimental Fermi velocities, enhancing understanding of their electronic structure.

Contribution

It provides a numerical analysis of low-energy excitations in cuprates, explaining experimental observations through a simple renormalized Fermi velocity model.

Findings

Nodal excitations show linear momentum dependence

Calculated Fermi velocities agree with experiments

Parameter dependence explained by renormalized Fermi velocity

Abstract

Motivated by recent photoemission experiments on cuprates, the low-lying excitations of a strongly correlated superconducting state are studied numerically. It is observed that along the nodal direction these low-lying one-particle excitations show a linear momentum dependence for a wide range of excitation energies and, thus, they do not present a kink-like structure. The nodal Fermi velocity $v_{\rm F}$, as well as other observables, are systematically evaluated directly from the calculated dispersions, and they are found to compare well with experiments. It is argued that the parameter dependence of $v_{\rm F}$ is quantitatively explained by a simple picture of a renormalized Fermi velocity.