Effective one-band models for the 1D cuprate Ba${}_{2-x}$Sr${}_x$CuO${}_{3+\delta }$

Adrian E. Feiguin, Christian Helman, Armando A. Aligia

We consider a multiband Hubbard model $H_m$ for Cu and O orbitals in Ba${}_{2-x}$Sr${}_x$CuO${}_{3+\delta }$ similar to the tree-band model for two-dimensional (2D) cuprates. The hopping param…