TITLE:
Electron Correlation in High Temperature Cuprates
AUTHORS:
Takashi Yanagisawa, Mitake Miyazaki, Kunihiko Yamaji
KEYWORDS:
High-Temperature Superconductor, Electron Correlation, Mott Insulator, Metal-Insulator Transition, Charge-Transfer Insulator
JOURNAL NAME:
Journal of Applied Mathematics and Physics,
Vol.2 No.5,
April
24,
2014
ABSTRACT: Electron correlation plays a key role in high-temperature cuprate superconductors. Material-parameter dependence of cuprates is important to clarify the mechanism of high temperature superconductivity. In this study, we examine the ground state of the three-band Hubbard model (d-p model) that explicitly includes oxygen p orbitals. We consider the half-filled case with the large
on-site Coulomb repulsion Ud by using the variational Monte Carlo method. The ground state is insulating when Ud is large at half-filling. The ground state undergoes a transition from a metal to a Mott insulator when the level difference εp-εd is increased.