High energy kink in the dispersion of a hole in an antiferromagnet -- double-occupancy effects on electronic excitations

TL;DR

This paper investigates how double-occupancy effects in the Hubbard model influence the electronic excitations and spectral features of holes in antiferromagnets, aligning theoretical predictions with recent ARPES and neutron-scattering experiments.

Contribution

It demonstrates that finite-U double-occupancy effects significantly enhance the observed spectral features and dispersion anomalies in cuprate antiferromagnets, supporting a unified Hubbard model description.

Findings

Enhanced kink in hole dispersion due to double-occupancy effects

Spectral-weight transfer between branches observed in calculations

Suppressed coherent spectral weight near k=(0,0) in agreement with experiments

Abstract

Evolution of the hole spectral function along the Gamma-(pi,pi) cut is studied in the antiferromagnetic state of the Hubbard model. The kink in the calculated hole dispersion, the sharp spectral-weight transfer between the branches, and the drastically suppressed coherent spectral weight near k=(0,0), as observed recently in the high-resolution ARPES studies of cuprate antiferromagnets, are shown to be strongly enhanced by finite-U double-occupancy effects. Together with the anomalous spin-wave dispersion observed earlier in high-resolution neutron-scattering studies, the present study provides further evidence of a unified description of magnetic and electronic excitations in cuprate antiferromagnets in terms of the Hubbard model.