Composite vs Constituent Particle Aspects of Hole Motion in the CuO2 Plane

Abstract

There is accumulating evidence that the CuO2 plane is responsible for both magnetism and superconductivity in several classes of oxide superconductors/1/. However, the question of what is the simplest model to describe the essential physics for the hole motion in this quasi-two-dimensional system, is still under active discussion. Anderson /2/ proposed in the early days of the Hi-Tc heat wave to use the one-band Hubbard model, according to which there is only one state per each unit cell. On the other hand, the experiments have shown clearly that the antiferromagnetic (AF) spins are located on Cu sites, while the additional holes reside on O sites/3/. Emery and several other authors/4/ have considered an extended Hubbard model which includes both Cu and O bands. Later, Zhang and Rice/5/ have shown that one can derive under certain assumptions an effective one-band model, starting from the two-band scheme. Their main observation is that the Cu-O hybridization binds a hole on each square of O atoms to the central Cu2+ ion to form a local singlet. Nevertheless, there is still no consensus on this issue/6/.KeywordsSinglet StateComposite ParticleCuO2 PlaneLinear Temperature DependenceKondo LatticeThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.