English

Determination of superexchange interactions for the CuO$_2$ chains in LiCu$_2$O$_2$

Strongly Correlated Electrons 2023-12-14 v1

Abstract

Starting from \textit{ab-initio} calculations, we derive a five-band Hubbard model to describe the CuO2_2 chains of LiCu2_2O2_2. This model is further simplified to a low-energy effective Heisenberg model with nearest-neighbor (NN) J1J_1, and next-nearest-neighbor (NNN) J2J_2 interactions, combining perturbation theory, exact diagonalization calculations and Density Matrix Renormalization Group results. For realistic parameters we find the corresponding values of these interactions. The obtained effective model is consistent with a spiral-magnetic ground state as experimentally observed. Using symmetry arguments, the spiral state is a sufficient condition for the ferroelectricity observed in the system.

Keywords

Cite

@article{arxiv.2212.03318,
  title  = {Determination of superexchange interactions for the CuO$_2$ chains in LiCu$_2$O$_2$},
  author = {N. Aucar Boidi and Christian Helman and Y. Núñez-Fernández and K. Hallberg and A. A. Aligia},
  journal= {arXiv preprint arXiv:2212.03318},
  year   = {2023}
}