Computational Study on the Ground State of a Dopant Hole in a Two-Dimensional Quantum Spin System

Abstract

In order to examine the Kamimura–Suwa model for the electronic structure of cuprates, computational study is made for a 4 ×4-site 2D square system. In this system the ground state of a dopant hole which is interacting with a two-dimensional quantum spin system is investigated numerically by the exact diagonalization method. Present numerical calculations show that antiferromagnetic ordering of the underlying host spins continues to exist even in the presence of a dopant hole. Allowing the dopant hole to adopt two kinds of orbital states through alternate Cu sites, the hole becomes itinerant, following the Kamimura–Suwa model. It is also shown in the case that the dopant hole occupies only a single orbital state b 1g , it tends to form a localized spin-polaron.