Role of oxygen-oxygen hopping in the three-band copper-oxide model: quasiparticle weight, metal insulator and magnetic phase boundaries, gap values and optical conductivity

TL;DR

This study examines how oxygen-oxygen hopping influences the three-band copper-oxide model, revealing minor effects on phase boundaries and quasiparticle properties but significant impact on magnetic phases and optical spectra.

Contribution

It demonstrates that oxygen-oxygen hopping has limited effect on some properties but crucial influence on magnetic and optical features in the model.

Findings

Phase boundary shifts by less than 0.5 eV with oxygen-oxygen hopping.

Quasiparticle weight remains similar across hopping variations.

Magnetic phase boundary and optical spectra depend significantly on oxygen-oxygen hopping.

Abstract

We investigate the effect of oxygen-oxygen hopping on the three-band copper-oxide model relevant to high-$T_c$ cuprates, finding that the physics is changed only slightly as the oxygen-oxygen hopping is varied. The location of the metal-insulator phase boundary in the plane of interaction strength and charge transfer energy shifts by $\sim 0.5$eV or less along the charge transfer axis, the quasiparticle weight has approximately the same magnitude and doping dependence and the qualitative characteristics of the electron-doped and hole-doped sides of the phase diagram do not change. The results confirm the identification of La$_2$CuO$_4$ as a material with intermediate correlation strength. However, the magnetic phase boundary as well as higher-energy features of the optical spectrum are found to depend on the magnitude of the oxygen-oxygen hopping. We compare our results to previously published one-band and three-band model calculations.