Spin-1 chain doped with mobile S=1/2 fermions

Beat Ammon, Masatoshi Imada

We investigate doping of a two-orbital chain with mobile $S=1/2$ fermions as a valid model for ${\mathrm{Y}}_{2-\mathrm{x}}\mathrm{C}{\mathrm{a}}_{\mathrm{x}}\mathrm{BaNi}{\mathrm{O}}_5$. The S=1 spins are stabilized by strong, ferromagnetic (fm)…