English

Diagonal superexchange in a simple square CuO$_2$ lattice

Strongly Correlated Electrons 2025-10-23 v4

Abstract

Many microscopic models with the interaction between the next-nearest neighbours as a key parameter for cuprate physics have inspired us to study the diagonal superexchange interaction in a CuO2_2 layer. Our investigation shows that models with extended hopping provide a correct representation of magnetic interactions only in a hypothetical square CuO2_2 layer, where the diagonal superexchange interaction with the next-nearest neighbors always has the AFM nature. The conclusions are based on the symmetry prohibition on FM contribution to the diagonal superexchange between the next-nearest neighbors for a simple square CuO2_2 layer rather than for a real CuO2_2 layer, where diagonal AFM superexchange may be overestimated. We also discuss the reasons for magnetic frustration effects and high sensitivity of spin nanoinhomogeneity to square symmetry breaking.

Cite

@article{arxiv.2501.17432,
  title  = {Diagonal superexchange in a simple square CuO$_2$ lattice},
  author = {V. A. Gavrichkov and S. I. Polukeev and S. G. Ovchinnikov},
  journal= {arXiv preprint arXiv:2501.17432},
  year   = {2025}
}

Comments

12 pages, 4 figures

R2 v1 2026-06-28T21:23:15.713Z