Inhomogeneous Electronic Distribution in High-Tc Cuprates

TL;DR

This paper models the doping effects in high-Tc cuprates, revealing inhomogeneous charge distribution and phase separation tendencies near half-filling using a three-band Hubbard model and Hartree-Fock approximation.

Contribution

It introduces a theoretical analysis of doping-induced inhomogeneity and phase separation in high-Tc cuprates based on a three-dimensional three-band Hubbard model.

Findings

Charge-transfer insulator-to-metal transition occurs with doping.

Doped carriers tend to form clusters near half-filling.

Microscopic phase separation between metallic and insulating regions is suggested.

Abstract

We theoretically investigate the doping evolution of the electronic state of high-Tc cuprate on both sides of the half-filling on the basis of the three-dimensional three-band Hubbard model with a layered structure using the Hartree-Fock approximation. Once a small amount of holes or electrons are doped into the half-filled state, our model exhibits the charge-transfer insulator-to-metal transition along with a chemical potential jump. At the same time, the doped holes or electrons are inhomogeneously distributed, and they tend to form clusters in the vicinity of the half-filling. This suggests the possibility of microscopic phase separation with the separation between the metallic and the insulating regions.