In this paper, from the microscopic Hubbard Hamiltonian we extract the local spin-singlet amplitude due to short-range spin correlations, and quantify its strength near half-filling. As a first application of the present approach, we study a problem of the energy dispersion and its d-wave modulation in the insulating cuprates, Sr2CuO2Cl2 and Ca2CuO2Cl2. Without any adjustable parameters, most puzzling issues are naturally and quantitatively explained within the present approach.
@article{arxiv.cond-mat/0005269,
title = {Short-range spin correlations and induced local spin-singlet amplitude in the Hubbard model},
author = {Bumsoo Kyung},
journal= {arXiv preprint arXiv:cond-mat/0005269},
year = {2009}
}