Spin Density Waves in Dimerized Systems

Abstract

We study the effect of strong electronic correlations in the presence of chemically-induced charge transfer. We consider the Hubbard model at half-filling with an external staggered field as the simplest model to investigate the condition for the existence of a spin density wave competing with a charge density wave. The slave-boson approach is used to treat the electronic correlations in the strong coupling regime. We also consider the effect of a Brillouin-zone boundary phonon via a dimerization of the hopping term, thus introducing a competition with a paramagnetic bond-alternating phase and determine the phase diagram.