Effective one-band electron-phonon Hamiltonian for nickel perovskites

Abstract

Inspired by recent experiments on the Sr-doped nickelates, $L{a}_{2-x}S{r}_{x}Ni{O}_4$, we propose a minimal microscopic model capable to describe the variety of the observed quasi-static charge/lattice modulations and the resulting magnetic and electronic-transport anomalies. Analyzing the motion of low-spin (s=1/2) holes in a high-spin (S=1) background as well as their their coupling to the in-plane oxygen phonon modes, we construct a sort of generalized Holstein t-J Hamiltonian for the $Ni{O}_2$ planes, which contains besides the rather complex ``composite-hole'' hopping part non-local spin-spin and hole-phonon interaction terms.

12 pages, LaTeX, submitted to Phys. Rev. B

References in corpus (2)

• Hole pairing and phonon dynamics in generalized 2D $t-J-$Holstein models
• Spin Dynamics of Hole Doped ${\mathrm{Y}}_{2-\mathrm{x}}\mathrm{C}{\mathrm{a}}_{\mathrm{x}}\mathrm{BaNi}{\mathrm{O}}_5$

Cited by in corpus (2)

• Optical absorption and single-particle excitations in the 2D Holstein t-J model
• Spin excitations in ferromagnetic manganites